Likely another silly question about fans

When powered by the Antec HCP 1000 and SATAs having something like 9-13A capacity, it should be more than plenty anyway, right? - Yes.

Post your build.

Case - http://store.antec.com/gaming-series/eleven-hundred-v2.html

You seem to be putting a hell of a lot of fans in it. For an i7 and one R9 290x.

I'd try without the corsair fans to start with.

You are correct: you can power ALL of those 8 fans from the mobo's 4-pin (PWM) fan ports, and not use the additional module for fan control. The total fan current consumption for all 8 is about 1.6 amps, with more at start-up, but that is pretty small compared to the total available from the PSU, The real limit is not that. The limit is that any ONE mobo fan port can normally supply power for up to TWO fans if you use a splitter; the limit on one port is the START-UP current for the fans, which is greater than the running current. As a precaution, I'd suggest putting the four AF120's (with their lower current consumption) on two mobo ports using two splitters. However, that may depend on which fans you want to have controlled by which mobo sensors.

What do I mean? Any mobo fan port, when set to use automatic control, uses a temperature sensor built into the mobo by its manufacturer and compares a real measured temperature to a target. It then alters the fan's speed to bring that measured temp to the desired setpoint. (Note that, although modern fans provide a speed signal output sent back to the mobo for monitoring and display, the automatic temperature control systems do NOT use that signal to achieve control.) On many advanced mobos now, the maker has built in more than one temp sensor and assigned certain ones to be used by certain ports. Some even tell you in the mobo manual where those temp sensors are and allow you to make your own assignments of which sensor guides which fan port. So YOU may need to do some arranging of sensors and ports, and that will impact your choices of which fans can be combined on one port using a splitter. If necessary, I'd expect it would be acceptable to combine one SP120 and one AF120 fan on one mobo port using a splitter, but I'd try to avoid two SP120's on one port.

For this purpose, you need a couple of 1-to-2 splitters specifically for 4-pin (PWM) fans. For example,

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423160&cm_re=4-pin_fan_splitter-_-12-423-160-_-Product

Note this unit has Pin #3 of ONE of its output connectors missing. This means that the speed signal from only ONE of the two fans is fed back to the mobo for monitoring, which is the correct way. (The other fan's speed simply is not monitored at all.) A splitter should not feed two different speed pulse signals into one mobo port, for that will cause the speed measurement system to become confused and generate false readings.

Setting the BIOS to use automatic control for all fans via mobo ports means you do not have to check and adjust fans manually all the time, and it's probably better than any manual fan control system. In fact, if you think you need different cooling from what the mobo's automatic systems provide, probably you will find that each of the automatic control systems can be custom-tuned rather than using the initial settings provided in BIOS,

I've got an old ASRock X79 mobo. It runs 3 pin fans on auto easy. I'd have thought the ROG would be even better.

OOOPS! Problem - likely. I did not realize that your SP120 fans are 3-pin type. In fact, as I check around, I find confusion! The Corsair website seems to say both the AF120 and the SP120 are 3-pin fan designs, but I also found retailers claiming some are 4-pin. Maybe there are several similar fan names with different specs? Check yours carefully to be sure.

Now, the problem is that normally any 3-pin fan plugged into a 4-pin port will ALWAYS operate at full speed. The mobo's automatic control system cannot change the speed of 3-pin fans on a 4-pin port. If that is your situation, you cannot use those fans connected to any mobo 4-pin port and expect speed to be controlled. You would be forced to use the auxiliary controller.

Now, there are exceptions, and you should check your mobo's manual carefully for any notes about this. SOME mobo fan 4-pin ports can be configured to operate EITHER as 4-pin ports (also called PWM Mode) OR as 3-pin ports (also called Voltage Control Mode). In fact, a few are even so "smart" they can figure out which fan type has been plugged in and make that adjustment automatically. BUT many mobos with this feature provide it ONLY on the port(s) used for the CPU_FAN cooling, and not for the CHA_FAN or SYS_FAN ports. So, check your mobo manual and see if it is possible to make your 4-pin CHA_FAN ports work as 3-pin (Voltage Controlled) ports that can control your fans' speeds.

Some mobos can run pwm or voltage control.

So I dug further and there is a good solution built into your mobo.

In your mobo's manual, p. 3-46 there are details of configuration of your 6 mobo CHA_FAN ports. ALL of them it appears, can be configured manually in BIOS Setup to use either PWM Mode (4-pin fan) or DC Mode (3-pin fans). Set them to DC Mode. (On the previous page you'll see that similar setting options are available for the two CPU_FAN ports.) Note also that you may need to set the temperature measurement probe used for such automatic control. The manual says it is set by default to CPU (which is odd, since we're talking about case fans), and you should ensure it is set to MB (motherboard temp sensor) for the 6 CHA_FAN ports. If you set this way, all your mobo CHA_FAN ports can be used to power and control automatically your 3-pin fans.

Since you have 3-pin fans, the splitter you need is not the one I posted earlier. Here is a sample of a 3-pin fan splitter (12" leads) that does the "only one fan speed connected" thing properly:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423169&cm_re=3-pin_fan_splitter-_-12-423-169-_-Product

I note the mobo specifies that each fan port can supply up to 1.0 amps for its connected fan(s). Thus, even if the starting current for each fan is double its running current, you could put two of any of your fans on one port using a splitter.