Can someone explain fan splitters?

Frozen CPU has been closed for quite awhile.

Tho I primarily use FCPU as a site to see what is available, (because the US competitor web sites are horrendously slow or stock limited), be aware that Frozen CPU re-opened about 6 months ago. I was advised i still have a credit on my account there, though I have not had cause to use it ... as i recall it's about $7

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I didn't know that, I wude invited you on our "geek pilgrimages" ... my son attended Cortland and we'd take "road trips up to visit".... saved bundle in shipping .. spent much more in gas but had fun.

I just called and spoke to "Kama" ... so doors are open. My youngest son is planning on Cortland maybe in January 2017 ... so i just may give ya a yell.

Yes, this is truly a Y-splitter for 4-pin fans. (I'll mention hubs later.)

You need to know a few things about fans and mobo headers to understand splitters and hubs.
1. There are two ways that computer fans can be powered and controlled by mobo headers.

(a) 3-pin fans are supplied with 3 connections: Ground on Pin #1 (Black wire), +DVC on Pin #2 (Red wire), and Speed Pulse on Pin #3 (Yellow wire). For these fans, the voltage on Pin #2 is varied from 12 VDC max down to about 5 VDC min. Supplying lower voltage may cause the fan to stall and fail to re-start until the voltage is raised. This is called Voltage Control Mode. The signal on Pin #3 is a series of pulses (2 per revolution) generated inside the fan motor and being sent back to the mobo for counting so it can display the speed for you. Usually also the mobo uses this signal for fault monitoring - that is, to be sure the fan is still working. But the mobo does not actually use the speed measurement to control the fan's speed.

(b) 4-pin fans (newer design) use very similar signals on the first three pins, and add a 4th pin carrying the PWM signal. The wire color codes on these is different from 3-pin wiring colors. The other difference is in the DC voltage on Pin #2. Instead of varying as 3-pin fans do it, this system keeps the Pin #2 voltage constantly at 12 VDC. Inside the motor case there is a small circuit that uses the PWM signal from Pin #4 to alter the flow of current from the 12 VDC supply through the motor, thus achieving speed control. This is called PWM Control Mode (or just PWM Mode). PWM fans have a couple of advantages over 3-pin fans: they can be run at slower minimum speeds without risking stalling, and they can start up reliably at settings less than maximum speed.

Mechanically, the connectors used for these two fan types are compatible. The male (pins sticking up) headers on the mobo have a plastic tongue sticking up beside the first 3 pins, and the female connector on the end of the fan wiring has a groove on one side to match this. Thus you can only connect them one way. 3- and 4-pin female connectors can plug into both 3- and 4-pin mobo headers. Electrically, the signals on the first three pins are the same (except for the DC supply voltage on Pin #2). So both mechanically and electrically they can be mis-matched and still work - sort of! If you plug a 4-pin fan into a 3-pin header, it will work and be under speed control. The fan won't get its PWM signal, but it WILL get a voltage that varies, thus changing the motor speed. The other way - that is 3-pin fan plugged into a 4-pin port - yields a fan that runs only at full speed all the time (no speed control), but at least it provides cooling air flow.

Mobo headers can be confusing. Many mobos have "fake" 4-pin SYS_FAN headers that have 4 pins sticking up, but electrically they operate only in Voltage Control Mode just like a 3-pin header, with a useless 4th pin. The idea is that, no matter what type of fan you plug in it will work (see the notes on "mis-matched" fans above), and you will not worry about it because the header has 4 pins. This only becomes a problem if you want to use such a header as a true 4-pin header that provides a PWM signal on Pin #4, which is necessary if you use a PWM Hub (see later). There are other systems used in some mobos that allow you to specify in BIOS Setup whether a 4-pin header will perform in Voltage Control Mode or in PWM Mode.

2. On virtually all mobo fan headers you encounter, the circuits can provide up to 1.0 amps at 12 VDC max to the fan(s) connected. Now, most common fans actually consume 0.1 to 0.2 amps when running at full speed, but can use 2 to 3 times that for a few seconds when starting up. So there's a "rule of thumb": you can connect up to TWO fans (normal ones) to any mobo fan header, but NOT MORE. That is why a Y-splitter with only two outputs can work. Although you can buy splitters with more than two output connectors, DO NOT use them!

Now we get to your specific questions, OP. The Y-splitter in your link is a 4-pin splitter. You plug the female connector (with 4 holes) into a mobo male header (with 4 pins). You then plug two fans' female connectors into the two male outputs of the splitter. If you look closely at the pictures, you will see that, of the two male outputs, only one has all 4 pins - the other is missing Pin #3. A mobo header's circuits can accept and count the speed pulse signals from only ONE fan, so a splitter must send to the header the speed signals from only one. The other fan's speed signals are ignored. This is the correct way to build a splitter.

The two fans will operate in parallel, sharing equally the voltage supplied and the PWM signal. They both will be under control by the mobo header.

Because of the connector design, you can plug both 3-pin and 4-pin fans into a 4-pin splitter. BUT, assuming you connected it to a mobo true 4-pin header operating in PWM Mode, any 3-pin fan plugged in this way will only run at full speed all the time (see mis-matching notes above).

Now, additional information on HUBS.

There are devices on the market now called 4-pin Fan Hubs that allow you to connect MORE than 2 fans to a single mobo header and control them all together. There are two key elements to do this.
(a) the Hub MUST obtain power for all its fans from a different source than the mobo header to evade the 1 amp limit. This means always that it has a cable with a connector on its end that plugs into a power output connector directly from the PSU that is intended for hard drives. This may be a "4-pin Molex female" connector (about ¾" wide with 4 round holes in a straight line), or a SATA Power connector. One such PSU output can provide power to MANY fans. The Hub does NOT connect the mobo header's Pjn #2 (DC supply voltage) to its fans.
(b) the Hub simply shares the PWM signal it gets from Pin #4 of the mobo header to all its fans - the circuit inside the fan case uses almost no power from this signal, so it does not overload the header circuit.
Thus a 4-pin Hub can be used to connect many fans to a single mobo header. The power comes from the PSU, but the control signal comes from the header.

A 4-pin PWM fan Hub can take two forms. The simplest to "see" is a box with wires from it and fan ports along its sides. But an alternative looks much like a simple splitter with one female fan connector to the mobo header and many male fan output connectors. The key difference is that it also has one cable that goes to a PSU power output connector. THIS is what makes it different from a multi-arm simple splitter.

There is no such thing as a 3-pin fan hub. In the 3-pin system, the control of speed is done by varying the voltage on Pin #2, and there is no high-power (current) source of such a voltage other than the limited mobo headers. The only exception to this that I know of is the Phanteks PWM Hub. It uses a must have a PWM signal from a mobo 4-pin header operating in PWM Mode, and it gets its power for all fans directly from the PSU, just like any 4-pin Fan Hub, However, it does not merely share out the PWM signal to 4-pin fans. Instead it uses its own circuits to create six true 3-pin fan headers operating in Voltage Control Mode. Thus it can control any mix of 3-pin and 4-pin fans plugged into it, based on the PWM signal from a single mobo 4-pin fan header.

JackNaylorPE posted a note about use of the Phanteks PWM Hub that contains a small error in my opinion. He suggests that you can use up to six 3-pin fans on the hub without plugging into the PSU using the power connector cord. That ignores the large temporary surge current used at start-up time. I believe that you should ALWAYS connect the Phateks Hub to a PSU power output.

FYI, the Phateks Hub has six output connectors (3 pin form) but says it can be used with up to 11 fans if you use 3-pin Y-connectors to connect 2 fans each to five of the ports. Like mobo fan headers, the Hub ports are subject to the "rule of thumb" of max 2 fans per port. The Hub also has an overall limit of max 30 W for all its fans in total. (The math works out to 30 W max load at start-up if you assume 11 fans at 12 VDC, each using 0.11 amps when running but using twice that for start-up.) The Hub comes with two 3-pin Y-splitters to get you started.

Almost ....

1. The Phanteks fan hub operates in PWM mode when used on a PWM Header. As you said, it converts the PWM signal into variable voltage control.

2. It is not recommended to control PWM devices from this hub, why would you pay more for a PWM fan anyway ? PWM control of 3 pin fans is the best of both worlds as it allows the use of cheaper fans and eliminated low speed PWM clicking and hum. Also, some PWM fans, notably Corsair, have issues with ganging 5 or more fans on a single channel whereby they lose all speed control.

This comes direct from Nidec (fan OEM) and Swiftech:

PWM speed control of a standard fan is indeed very different from PWM speed control of a PWM fan… Nidec even goes so far as to say that modulating the main supply voltage is not advisable:

Pulse-width modulation of DC operating voltage to modify fan speed [edit: in PWM devices] is not recommended. Transients generated by that approach can irreversibly damage motor commutation and control electronics and dramatically shorten the life of a fan.

As we can see above, it is critically important to distinguish between PWM fan controllers designed to manage regular 3 pin fan, and PWM fan controllers specifically designed to manage 4 pin PWM fans. In the first type, the 12v supply line is modulated by the fan controller and in the second type the controller sends a signal thru the 4th wire to the fan, and the fan motor modulates its speed according to this signal by using its onboard controller.

What is important to understand above is that PWM fans, and the Swiftech PWM pump, are designed to receive a fixed 12 v supply.

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3. Early models of the hub used a molex connector, newer models use SATA power connector.

4. The Phanteks hub also operates directly off the MoBo headers w/o the power connector. As long as the number of fans used does not exceed the 1 amp header rating (2 amps on some enthusiast boards), the aux power connector is not required.

5. In fact, if you do connect the auxillary power connector when using a DCV header, speed control vanishes. The signal from the power connector is a constant 12v volts which is passed onto the fans telling them to go at full speed.

6. There are in fact 3 pin hubs, a substantial line of which is made by ModMyToys.

http://www.modmytoys.com/pcb.html

3-Pin Male to 3 x 3-pin Male
3-Pin Male to 4 x 3-pin Male + 4 x 2-pin Male
3-Pin Male to 5 x 3-pin Male

3pin: Please make sure you do not exceed your 3-pin fan headers maximum wattage by overloading more high wattage fans then the motherboard or fan controller can handle. Please consult your products manual.

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7. There is absolutely no issue with using more than 2 fans on a MoBo header .. have dozens of builds in use with more. I have been using three Phanteks fan hubs for 2.5 years in our test bed

Channel 0
PWM CPU Header => Swiftech Dual 35x2 Water Pumps

Channel 1 (6 fans @ 0.14 amps = 0.84 amps)
DCV Sys Header 1 => Phanteks Hub 1 => Six (6) Phanteks 140mm 1250 rpm fans on 420mm radiator

Channel 2 (4 fans @ 0.14 amps = 0.56 amps)
DCV Sys Header 2 => Phanteks Hub 2 => Four (4) Phanteks 140mm 1250 rpm fans on 280mm radiator

Channel 3 (6 fans @ 0.14 amps = 0.84 amps)
DCV Sys Header 3 => Phanteks Hub 3 => Six (6) Phanteks 140mm 1250 rpm case fans

Before I had the 2nd and 3rd hubs, and added push / pull (about 8 months after initial build). I had a total of eight (8) fans (1.12 amps) running off a single header. Yes, i know it exceeded header rating... and I have seen blown headers before, but I was not concerned given just 12% over rated load on a hi quality enthusiast MoBo.

My son's 970 SLI build also has six (6) case fans (before he installed the Swiftech h240-X it was eight) on a Phanteks PCB running off a single DCV MoBo header in an Enthoo Luxe. Wife uses an Enthoo pro w/ five (5) fans running off a DCV Header. Again, none of the five (5) hubs uses the aux power connector.

Should you de-rate the hub for inrush current ? I do to a small extent and more so for higher rpm fans. At 1250 rpm for example, I like to limit it to 5/6 amps. But, having contacted MoBo, fan and hub manufacturers ... they all indicate that this is not necessary. When they say that their header is rated at 1 amp, they mean you can connect up to 1 amp of continuous load... not 1 amp worth of inrush current.

This is no different then typical circuit design. When we design treatment plants, the motors will typically draw 6 to 10 times running load at startup. Yet we don't consider this momentary inrush to size the circuit breakers. It does have an effect on generator sizing as after a power outage, all connected motor loads wishing to all draw that inrush current at the same instant in time. So we use time delays for motor starts such that motors start in sequence, largest to smallest.

The general rule is to specify a circuit breaker rated at 100% of the continuous or average load.

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There is no error, just a misunderstanding as to what "rating" means. As per above, the header is rated for 1 amp of continuous power. A circuit breaker "blows" using a thermal or thermal magnetic trip.... when your fridge turns on, the inrush current is huge... but it doesn't trip the breaker because it is designed to provide a delay which is longer than the duration of the inrush current. When you have a 120 watt rated lamp, do you limit bulb wattage to 60 watts because of inrush current ? No the rating of the lamp is based upon 120 watts of continuous power and the manufacturer is well aware that more current / amps will occur at startup. The inrush current of a freezers 4+ times that of its running current ... but you don't see circuit breakers being sized for 4 times the running load.

A MoBo header blows when heat builds up to a point to melt or otherwise damage something. Because the inrush current duration is in milliseconds, heat never gets chance to build up and create an issue.

As indicated above, I have had 8 fans in operation off a single 1 amp header for months, and tho I can't say that 1.12 amps is 'recommended', I have had 6 fans running on numerous boxes for years. If you had 7 (0.98 amps), the manufacturer would be bound to honor your MoBo warranty.

Again, connecting the power cable to the hub when used on a DCV header renders it useless. All fans run at 100% speed as soon as the cable is connected. I did exactly that on my 1st build with the hub and was like WTH ? I wrote to Phanteks Tech Support asking why I had no speed control .... and 20 seconds after hitting "send", i wrote a followup saying "I'm an idiot" ... with no PWM signal, the hub circuitry has no input with which to convert into speed control adjustments. The variable voltage signal from the header is overridden by the constant 12v from the power connector.

There really is no 2 fan rule of thumb ... with radiator fan amperage ranging from 0.1 amps to 0.5+ amps, there couldn't be.

Asus and MSI TS (MoBo) both responded that 1 amp continuous power is fine
Phanteks (Hub) responded that 1 amp continuous power input to the hub's "signal input" is fine.

In the old days, when peeps were using 0.5 amp fans on high fpi radiators, a 2 fan limit would be appropriate ... since today the focus is on quiet, low - medium fpi rads, there is no need for anything greater than 1250 rpm (outside of CLCs with cheap aluminum rads).

The proof is in the pudding ... in this room I have 5 Hubs running 4 - 6 fans each. Many more systems we built are also out there w/o issue.

ModMyToys and all the other hub manufacturers would have quite a disaster on their hands if their 3,4 5 way splitters were frying MoBo headers.

Very interesting post, JackNaylorPE. My comments follow.

Item 2 - I agree that there is little reason to use 4-pin fans on the Phanteks PWM Hub since its outputs are all in Voltage Control Mode and 4-pin fans typically are more expensive. My point was simply that you can mix if you want to for any odd reason. I also fully understand that a PWM-modulated DC power supply should NEVER be provided to a computer cooling fan, either 3-pin or 4-pin, because such fans require a stable clean DC voltage without transients. These computer fans with brushless motors are NOT anything like the standard DC motors that Electrical Engineers and motor control professionals use with PWM power supplies for speed control.

Item 4 - yes, the Phanteks Hub will operate without connection to the PSU for power, but then it is subject to the limit of power available from the mobo header. I find in VERY interesting that you have been successful in using many more than 2 fans on mobo headers this way, and that some mobo makers have told you that start-up surge current is not an issue for their products. Whether or not it is an issue depends on the details of the circuit elements supplying the current to the load. Of course, fuses and breakers in home appliances, lighting, and even large industrial motors are designed to allow for such surges. For the most part, they can do this because they represent relatively large heat "sinks" that can absorb a modest heat surge with no trouble. In the case of mobo fan headers, the limiting elements are microscopic transistor junctions in an IC chip, so I don't have a good "feel" for how much overloading they can tolerate. I understood that to be a small tolerance, but you have experienced success repeatedly with those kinds of start-up operations.

Item 5 - yes, I understand that connecting the Hub to a PSU output at a fixed 12 VDC would make the Hub useless for controlling fans IF that hub is connected to a 3-pin mobo header operating in Voltage Control Mode. Phanteks particularly warns against this. Their manual points out that doing this will result in all fans at full speed as you say. They emphasize that, to ensure control, the Hub's connection to a mobo port MUST be to a 4-pin header that IS using PWM Mode. In fact, given the fact that so many mobos contain "fake" 4-pin SYS_FAN headers that are actually 3-pin Voltage Control Mode headers with an unused Pin #4 (i.e., no PWM signal), they recommend that ALL users connect their Hub only to a CPU_FAN header. That is because almost all mobos today are sure to operate that header in PWM Mode, or at least to make PWM Mode the default setting with Voltage Control as a second option. That recommendation causes some consternation to users who want to use the Hub solely for case ventilation fans and don't understand the limits and reasons for what the manual says.

Item 6 - I don't consider the ModMyToys units Fan Hubs, but merely multi-output fan splitters. My use of those terms is that a splitter simply connects two or more loads to a common source so that they run in parallel powered completely by the source. I note that ModMyToys specifically reminds users to ensure their total load connected does not exceed the mobo maker's limit for the header, thus limiting their liability. Like most others, they do not discuss any detail about whether "load" means peak surge load or continuous running load. A Hub, on the other hand, obtains its power for all loads from a different source that can provide all the power needed by the load, and separately provides some method of applying a common control to the loads. Most 4-pin fan Hubs uses simple sharing of the PWM signal, but the Phanteks PWM Hub does it differently, as we've been discussing.

One final point of max loading. The Phanteks PWM Hub manual specifically says that it is limited to 30 W total load, and also that it can be used with UP TO 11 fans connected to its six ports, using simple 2-output 3-pin Y-splitters. Even at a continuous load rating of 0.15 amps per 12-volt fan, 11 fans comes to 19.8 W. They appear to be saying you should NOT connect up to 30 W of continuous fan motor load to the Hub.

Item 2 - The recommendation comes from Nidec, specifically for PC Fans.... the quote was from the Nidec site. When a fan manufacturer who has to warranty something says "don't do this", I'm not going to do it. It must be said however, that I think they have little to worry about, if a fan fails, user will generally write it off and most won't fail within the typical design life of the PC.

Item 4 - the 2 rule rule of thumb does not exist. MoBo manufacturers specifically state that the header rating is based upon the continuous voltage rating". We see the same thing with cooling where folks look at an instantaneous peak of a video card and begin insisting that the PSU will blow up or the cooling will fail if you don't size them for twice the TDP. No ... the TDP is the TDP, yes you may see peaks up to twice the TDP ... that's what caps are for. I have demonstrated this on the test bench by measuring the power output at the wall with a power meter. These short peaks simply do not register on the meter.

The 2 x peaks are ms in length and do not change the average required cooling load. We have 6 temp sensors in the test rig along with the power meter. We can easily measure the wattage at the wall and the corresponding increases in water temps in the loop... with and without the cards in play.

Let's do the math...

Peak power output of Asus 970 = 268 watts (add 10% when MSI AB slider power limiter slid to 110% = 295
http://www.techpowerup.com/reviews/ASUS/GeForce_GTX_780_Direct_Cu_II_OC/24.html

780 GFX w/ 26% OC = 295 x 2 = 590 watts
CPU @ 4.7 Ghz (1.385 VID) = 130 watts
Water pumps = 2 x 23 watts
MoBo = 40 watts
RAM = 10 watts
2 x SSDs = 8 watts
2 x SSHDs = 20 watts
16 fans = 2 watts

http://www.tomshardware.com/reviews/power-supply-psu-review,2916-8.html

BTW, if ya read the article... you see any mention of worrying about "inrush current" ?

Now lets compare that 846 watts with the power meter ... the meter tops out at 745 watts under Furmark.... allowing for the efficiency of the PSU, let's be real generous here and call it 90%, ... 745 a 90% = 680 watts. So wait ... why isn't it up at 850 watts and instead 170 watts less ?

If the GFX cards are drawing 590 watts ? ... that means everything on the PC is drawing only 90 watts .. that simply "isn't real".

On the heat measurement side, we see the same thing. We don't see Delta T rising in an amount that corresponds to 590 watts.

Not only I have I had success, repeatedly and w/o exception, I have never heard of a single failure. Inquiries to Tech Support from multiple MoBo manufacturers say the rating is for continuous voltage. Now if the people who build the thing say say that only the continuous rating matters and they say that they support up to 1 amp of continuous power, that they will have to replace the board if it fails with < 1.0 amp of continuous voltage .. where does this 2 fan thing come from ?

item 5 - Like the 2 fan rule of thumb, the warnings you speak of simply don't exist ... they are not "in the manual" as claimed.

Connecting the 4-pin to other 4-pin header (besides the CPU_Fan)

Other 4-pin connectors can be found on modern motherboards besides the “CPU_Fan” connector (e.g. “CPU_Fan2”, “CHA_Fan”, “OPT_Fan”), however not all motherboard manufacturers implement a true PWM signal modulation onto these connectors. These type of 4-pin connectors modulate the RPM by voltage, which has a smaller control range compared to modulation by true PWM signal.

The 12V SATA power cable can not be used to power the PWM hub if connecting to these types of 4-pin connectors, due to the interference with the RPM regulation by voltage (resulting in the fans running on full RPM). The PWM hub will draw its power from the 4-pin connector, which is limited to a total device consuming 30W in total.

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So no the statements below are false...there are no such warnings ... it merely says that PWM offers a greater control range and not to connect the power cable if using DCV.

They emphasize that, to ensure control, the Hub's connection to a mobo port MUST be to a 4-pin header that IS using PWM Mode....

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Simply not true as the manual states. PWM range is typically take as having a bottom end of 25% speed... it's generally somewhat higher with DCV... usually in the low to mid 30s so the control range is slightly smaller. However, with Asus FanXpert doing the fan profile, it sets the bottom with Phanteks DCV fans from 282 to 326 fpm .. that's 22 - 26%.

Why would they tell you how to use a the power cable when connected to DCV if you MUST use a PWM Header ?

they recommend that ALL users connect their Hub only to a CPU_FAN header.

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Where ? The manual does not include this recommendation. It explicitly says that if you want to do this, don't connect the power cable and don't exceed 30 watts.

Point of Information ... they are not "fake" 4 pin headers. You stated repeatedly that PWM can be used on DCV headers ... Though fan manufacturers discourage this when used in critical applications, the resulting impact of the practice will not frequently manifest itself within the fan's typical warranty period. In addition, Z87 motherboards typify this 4 pin header but only DCV voltage control phenomenon. The origin of which becomes evident when you read the MoBo manuals. And, for example, the RoG line manuals describe these headers as PWM.

When I contacted Asus TS after determining that no PWM control existed on these headers, they advised that the Z97 boards would have dual control options .. the header would work with either PWM or DCV with either auto detect or BIOS setting. That would require a 4 pin header.

This was expected to be incorporated as a feature on the Z87 boards, but they never quite got the bugs out in time for release so it was scrapped ... unfortunately, either the manuals were already printed or no one remembered to go back and edit them when the feature was ultimately omitted.

they recommend that ALL users connect their Hub only to a CPU_FAN header. ... That recommendation causes some consternation to users who want to use the Hub solely for case ventilation fans and don't understand the limits and reasons for what the manual says.

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Again, the manual does not say that.... anywhere.

Originally, when the Phanteks cases were released, there was no intention to release the hub as a separate accessory. We, and other users participating the the Enthoo thread on overclock.net, were building Enthoo based builds at a time when there were no or insufficient PWM headers available for water cooled systems. In my box, the CPU and CPU_OPT were taken by the twin water pumps. I had no headers available for **any** fans. TS advised to just connect them to the DCV headers.

After Phanteks was convinced to release the hub as an accessory, they went thru several months of testing as the plastic cover, alternate power source and universal mounting methods were evaluated. Phanteks TS was very active in the thread as this and "recommendations for version 2" of the cases / accessories were discussed.

We kept pestering them to sell us two "Phanteks case style" units as "replacements" w/o success. Finally, Phanteks provided us with two extra hubs "for testing" free of charge. We worked under the direction of Phanteks TS thru the entire testing procedure and thus are very familiar with their "recommendations". The ones you stated, do not appear in the manual, nor were they ever stated to us; the manual and everything we received is in direct conflict with your statements.

Item 6 - You are free to consider anything your choose, but a statement that a device does not exist should be qualified by saying "To my mind .." because the industry says otherwise.

My use of those terms is that a splitter simply connects two or more loads to a common source

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Ya mean like a PC network hub that lets you connect multiple computers to a common source ?

"Definition Hub: 3. (Computer Science) computing a device for connecting computers in a network

"Definition Hub: 6. any one of the holes in an electrical panel, into which connections may be plugged."

Thermaltake, Swiftech, NZXT, Deepcool, Silverstone, Swiftech all have fan hubs on the market

http://www.deepcool.com/product/dcoolingaccessory/accessory/2013-12/48_663.shtml
http://www.performance-pcs.com/internal-power-distribution-pcb-10-way-3-pin-fan-hub-power-splitter-25054.html
http://www.performance-pcs.com/silverstone-cpf04-1-to-8-pwm-fan-hub-black.html
http://www.aliexpress.com/item/1-8-CE-ZIF-50pin-IDE-to-SATA-22pin-Adaptor-Converter-2in1/431004672.html?spm=2114.40010308.4.8.UsETPs
http://www.ebay.com/itm/1-4pin-to-4-Port-host-case-cpu-PC-Fan-Hub-Splitter-cable-for-Multi-Way-PWM-Fan-/311502444768?hash=item4886fe18e0:g:MZwAAOSwmrlUurTS

The generally accepted distinction between a splitter and hub is that a splitter is a cable with one 'in' connector and multiple outs, A hub is a "central point"... the classical definition of the word hub, where all the connections are in one place ... a hub has no wires. Like a bicycle wheel, the "hub" is where the spokes come and meet.

The Phanteks hub is simply more than just a hub as the classic definition of hub is just "central location where things come together". In addition to serving as a hub the device acts as signal converter and source of auxilliary power. No where are those additional functions described / defined as being necessary to be a hub. A network hub doesn't convert the signal .. it doesn't add auxilliary power to make the connected devises function.

A Hub, on the other hand, obtains its power for all loads from a different source that can provide all the power needed by the load, and separately provides some method of applying a common control to the loads. Most 4-pin fan Hubs uses simple sharing of the PWM signal, but the Phanteks PWM Hub does it differently, as we've been discussing.

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So by your definition, the Phanteks device...

1. When it works as PWM with 11 fans and auxilliary power, it's a hub
2. When it works as PWM with 2 (or more) fans and no auxilliary power, it's not a hub
3. When it works as DCV* with 2 (or more) fans and auxilliary power, it's not a hub
* as specifically describe in the Hub Manual.

Why does Deepcool and all the others think their hub is a hub, it doesn't have power, it doesn't convert signals. The dictionary and industry standard definition differs from yours. The words splitter and PCB may also be used and they do accurately describe the devices... but so does hub.

I note that ModMyToys specifically reminds users to ensure their total load connected does not exceed the mobo maker's limit for the header, thus limiting their liability. Like most others, they do not discuss any detail about whether "load" means peak surge load or continuous running load.

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They don't say anything about in rush current ... which **if it was a "concern" or the deciding factor in a warranty dispute, they certainly would be required to do so.

1. The header has a published rating
2. The fan has a published rating
3. The published ratings are available to the consumer.
4. The consumers responsibility, as established by the warning, requires him / her only to examine the published ratings. They are not expected to take courses in electrical engineering, read textbooks or perform calculations.

If inrush current was an issue, ModMyToys and the MoBo manufacturer would be required to make that information available to the consumer. Otherwise, if we accept your premise, when I blew up my MoBo header with the 6 fans connected to it, they would be required to replace it.

Again, the proof is in the pudding ...

1. We have three boxes, all under extreme loads, with more than 2 fans using continuous rate voltage as the limiting criteria.... no problems. I had 8 fans going for a month... if inrush current was a 'thing" to be concerned about, how did the 7.84 amp inrush current not blow the board ... or the 94 watt wattage not blow the hub w/ the 30 watt max rating exceeded by a factor of 3 ?

I like to de-rate the header to provide a cushion as 1) out boxes are put thru some rather extreme conditions such as torture test runs with no fans running, repeated restarts and we have our fans set to shut off when temperatures are low. When Asus FanXperrt does the fan profiling it repeatedly shuts the fans on and off to determine the minimum operating rpms. So how did my motherboard header manage to survive not just one but a continuous series of fan restarts with a 4.5 amp inrush current ?

2. All of our builds for users that we have done, none have had a problem

3. All of the users in the Enthoo thread over on overclock.net ... no one has blown a header.

4. No reports of blown headers on Phanteks web site

5. No reports of blown headers in discussions with Phanteks tech support.

6. How is it that we see fan splitters on the market with 3, 4 and 5 connections ? Wouldn't there be a wave of "I blew my fan header" posts on forums ?

7. Why do highly respected enthusiasts vendors make custom sleeved cable splitters with 3 ,4 ,5 connections ? Is it possible that if inrush current was an issue, that these people who "do this for a living" are not aware of it ?

8. With all these vendors selling these splitters and hubs for so many years ... why can't we find innunmerable posts on blown fan headers ?

One final point of max loading. The Phanteks PWM Hub manual specifically says that it is limited to 30 W total load, and also that it can be used with UP TO 11 fans connected to its six ports, using simple 2-output 3-pin Y-splitters. Even at a continuous load rating of 0.15 amps per 12-volt fan, 11 fans comes to 19.8 W. They appear to be saying you should NOT connect up to 30 W of continuous fan motor load to the Hub.

Click to expand...

No, that's not what they are saying. They are saying, don't connect even 1 of these:

http://www.frozencpu.com/products/8147/fan-500/Delta_Mega_Fast_120mm_x_38mm_Fan_-_252_CFM_-_Bare_Lead_PFB1212UHE-F00.html?tl=g36c15s562

Or more than 3 of these:

http://www.frozencpu.com/products/7759/fan-471/Delta_120_x_25mm_Extreme_High-Speed_Fan_-_15033_CFM_FFB1212EH_Bare_Wire.html?tl=g36c15s60

or more than 8 of these

http://www.frozencpu.com/products/24857/fan-1365/Noctua_Industrial_NF-F12_120_x_25mm_PWM_Fan_-_3000_RPM_NFF12IPPC30P.html?tl=c365s936b32

I know what's coming .. that these fans are not normally used. But they are. Delta fans have been very popular over the years for radiator and even air cooler usage. A typical case 1200 rpm case fan may use 0.15 amps but high SP, high rpm radiator fans are higher.... much higher. Phanteks, as a manufacturer is specifically focused on accommodating the water cooling community so accommodation of radiator fans would be a necessity. And Noctua is certainly no stranger to the PC world.

Test sites evaluate coolers by attaching delta fans. Again, these fans are commonly used for radiator and air coolers to improve cooling performance. I wouldn't wanna use more than 3 or maybe 4 if ya stretch it a bit (7.56 watts) of those.

http://archive.benchmarkreviews.com/index.php?option=com_content&task=view&id=674&Itemid=62&limit=1&limitstart=4

Again, consideration of inrush current is a logical pursuit that would only come to mind by someone with considerable knowledge on the subject. However, marketing materials are not prepared on the basis of a highly knowledgeable consumer.The standard of care is to make it understandable to the average consumer.

The "MoBo Header Rating" is to be compared with the fans continuous voltage rating. The people who design the motherboards, fans and hubs, know all about inrush current. The ratings are based upon them being satisfied that the inrush current of fans, because of the extremely short duration, will not be an issue.

If all of this wasn't true, and inrush current was an issue, it would be quite easy to find a web site article on the subject. It would be quite easy to find forum posts with users ranting that that the complied with the ratings and they blew up their headers. But neither exists.

I'll keep this short - I don't want to continue hijacking this thread.

I looked up the Phanetks PWM Hub manual so I could quote the relevant sections, and I find it is new! The manual on their website now is much smaller and quite different from the one I used to see. You may not believe that, but it's true.

This new manual does not say you should only connect to the CPU_FAN header. It is actually better than the old version in explaining why a SYS_FAN header may not work. The issue of ability to control at the low end of speed range is not vital to whether or not it works at all. But they do make it clear that IF you use a 4-pin header that does NOT provide actual PWM control, AND if you plug the Hub's power connector into a PSU output, you will get no control and all fans will run at full speed. It recommends that, if you do connect the Hub to such a fan header (with Voltage Control, not PWM) you should not connect it to the PSU; I fully agree. THUS, IF you want to achieve control of the fans and use all the Hub's output capacity, you MUST use a mobo header that DOES provide PWM control and you MUST connect it to a PSU power source. I will note that the last sentence of the second-last paragraph seems to say that, when NOT connected to a PSU power source so that the only power available from the Hub is from the mobo header, the power limit is 30W! I definitely think this is written incorrectly - there's no logic to that when the mobo header is limited to 12W. Do you really think the Hub can magically expand the mobo's power limit that much?

I recognize that the ASUS Z97 mobo line is NOT using those headers I call "fake 4-pin". I think all of that line do use SYS_FAN headers that can be configured to operate in either mode. I think of them as 4-pin headers that can be "downgraded" to 3-pin at the user's choice, and that is very handy for some. In fact, many mobos in that line have superb additional flexibility and many SYS_FAN ports to use.

You have said several mobo makers have responded to your queries to assure you that the 1 amp limit for their mobo fan headers applies to continuous CURRENT (not Voltage) to the load and not to surge current at start-up. You also claim this is in "published ratings" which I have never see in manuals or in Specification listing on websites. The information given you by Tech Support people is the first time I have seen it stated that clearly.

I fully understand and agree with you that there ARE some fans on the market with much higher current consumption and those need special attention in designing a system. I often see posts from enthusiasts who want to use many high-power and high-airflow fans, and I'm not sure they know why. But they will use them anyway.

I have read some of the answers but i couldn't find a definite answer for my case, i don't wanna create a whole new thread for a similar question so i'm gonna ask here:
I ordered 4500 rpm Sunon fans, i'm weird and not bothered by noise at all, and i think they require 1 amp to run. So can i use this splitter or would it blow up?

What is the goal here ... ya trying to levitate the case off the desk ?

Those fans are 1 amp .... each. I would not under any circumstances connect them to a MoBo header rated at 1 amp all by themselves let alone use a hub or splitter.

The entire hub is rated at only 2.5 amps. So that means if you connected 2, you're done. You would have to use the SATA power cable to not blow the header and if you do that, it would have to be a PWM header

What I saw on the Sunon website suggests their fans are not designed for use in common desktop systems. They appear not to have any common fan connector and no speed signal output. They make no mention of PWM capability, and NOTE that what we in the computer "Club" call "PWM fans" are NOT what an electrical engineer would plan to use with a PWM power supply for a variable-s[peed DC drive! There is also no info on how these fans might work at reduced voltages if that were used fro speed control. In fact, I suspect their intent is that one would NOT attempt to control their speeds at all. They intend that these fans be supplied only with their rated voltage to run full speed all the time.

As JackNaylorPE said, those fans should NOT be plugged into any mobo header. You might power a few from a PSU's female 4-pin Molex output, which can supply several amps from its 12 VDC lines. To do that you'll probably have to arrange your own connectors. And I'd suggest you check into just how much load those 12 VDC supply lines and their PSU bus can handle in addition to what else it drawing power from the PSU's 12 VDC bus.

Well a friend said these hub connectors' sockets might not handle that much even if i get them 12V connection through the PSU. He means individual sockets, 1 of 6 on the hub. How true is this? Also i'm triying to move air through 60 mm radiators and i don't think 3000 rpm fans can do that, to be candid though i'm only guessing

Here's the issue with a Hub. SOME of them - especially the fancier ones with their own active circuit components - are limited in exactly the same way as are normal mobo fan headers. Their individual output circuits can only supply up to 1.0 amps per port. The very simple PWM 4-pin system Hubs that look just like several arms of wires with output male connectors, plus one input arm and one arm to the PSU for power, MAY be able to to do the job because they have no active circuit elements to limit you. BUT they do have a limit in the size of the wires used to build those arms, and it may be hard to figure that one out.

Still there is the larger problem that you have not figured out. Those Sunon fans I looked at do NOT appear to be designed the same as what we all are used to calling computer case ventilation "4-pin PWM Fans". They do NOT appear to have the necessary internal PWM modulation circuit devices, nor the speed feedback line, nor even the same kind of connector on their wires. So I do not expect that you could control them using a Hub and a 4-pin mobo header, even if you got those devices and tried to hook them up to those fans. I suspect your ONLY option would be to arrange to connect them directly to PSU fixed +12 VDC power supply lines and let them run full speed with no speed control option.