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Water Cooling: Closed Loop Vs. Open Loop

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July 16, 2014 7:32:29 AM

Hello everyone,

Up until now I have not had much need for Water Coolers. I have toyed around with a few Closed loops because they are easy to install and use but for the most part I have found Air coolers to meet my needs.

However... I am now looking longingly at AMD's FX9000 series and there is no way that I would imagine using an air cooler for that beast. so if I pick one up I want to certainly go the watercooling route. That being said I need to bone up on my water cooling knowledge. So for starters what would be the pros and cons of a closed system like the Corsair H100i Vs an Open system?

Any insights or experiences you can share will be appreciated.
July 16, 2014 3:33:11 PM

sweet, this is just the question for me!

ill start with some pros and cons,

pros about closed: its easy to install, minimum fear for leakage and you do not need to change the tubing and coolant every once in a while (around a year)

cons about a closed loop: you cannot expand it if you want more radiators or more waterblocks, they are rarely found for GPU's and you cannot customize it.

pros about a open loop: you can make it just how you want it, add more waterblocks, remove them or add more radiators, it looks better and because you can change out the radiators you can make it cool better.

cons about a open loop: you need to change tubing and coolant once in a while ( again, this can be one a year or even once every 2 years), it costs considerably more then a simple closed loop and it can leak if you do not connect it properly.

there are some more pros and cons about both but i do not want to make this too long, you can always ask them if you want.

if you are not that much into the looks of your PC and want a decent performance and no maintenance once every year or 2, a closed loop would be cool.
however, a open loop can be customized to work with a GPU too ofcourse, that way you can cool and maybe overclock both if you are into that.

i have a friend who uses a H100 and he has a pretty nice overclock and good temperatures too.
i however have a open loop that is now cooling my i5-2320 overclocked @ 3,7 GHz, with a 360MM (3 fans wide) double thick radiator.
i get great temperatures and my CPU has no problem running on the highest overclock i could get it to.

i currently have my system running for 1 year now with this loop and i have had no problems with leaks, i have just ordered new tubing for my new watercooling box project.

i have spend 300 euro ( 350 dollar roughly ) on this loop and when i want my GPU to be watercooled too i just need to buy a waterblock and 2 fittings, it costs about 150 dollar then but then i have fully integrated my GPU in my loop.

basically, there are pros and cons about a open loop, but it all comes to what you think. do you want to customize? do you want to watercool more components? do you want to make it run cooler?

i hope i helped and informed you a bit with my knowledge, if you want any more information that i forgot or if you want to hear more about my experiences, i would be glad to help you out!

if there is one thing i love it's talking about water cooling ;D

-Skywere


July 16, 2014 4:41:26 PM

Personally, I believe in air cooling. You could spend less, and unless you want it just because it looks cool, or because you are an extreme overclocker. Why go for an h100i, just an nh-d15. It will take up alot of space, so for mini itx scenarios, it might be good, but not always. Closed loop cooler can hardly ever upgraded. Even something like a 9590 could be cooled by an nhd14 (if you have the space.) Air cooling is sometimes quiet, with a good cooler. Maybe it is because I am still a teenager and can't afford a water cooler with my own money, but I would go air cooling for now.
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July 16, 2014 8:29:02 PM

@ Skywere: thank you very much for the response. One of my interests was determining how much more of a performance boost a custom loop would provide an whether it was worth the exta cost. From what you have explained its obvious a custom system would provide that because I could install multiple radiators that would provide more cooling. I am leaning towards a closed loop because I very much like the idea of less maintenance, I love building them but once the system is finished I would prefer to not have to do much more then blow the dust out periodically.

On the other hand I really dont know what kind of stress a 220W chip will put on a cooling system and I am nervous that a closed loop wont be enough. Additionally I really like the idea of cooling the graphics card so I haven't written off a custom loop yet. from what I can see on youtube they dont look difficult to install. they are just much more expensive.

@Pcbuilder123: Normally I am right with you, I typically trust air cooling for all my needs and have seen excellent results. My Xenon rarely tops 40c even when running dozens of aps an games simultaneously. That being said, I am looking at water cooling specifically because of the FX9000 series chips which clock in at 220W at stock speed. I am not confidant that an air cooler will be sufficient.
July 16, 2014 8:35:59 PM

DHFF said:
@ Skywere: thank you very much for the response. One of my interests was determining how much more of a performance boost a custom loop would provide an whether it was worth the exta cost. From what you have explained its obvious a custom system would provide that because I could install multiple radiators that would provide more cooling. I am leaning towards a closed loop because I very much like the idea of less maintenance, I love building them but once the system is finished I would prefer to not have to do much more then blow the dust out periodically.

On the other hand I really dont know what kind of stress a 220W chip will put on a cooling system and I am nervous that a closed loop wont be enough. Additionally I really like the idea of cooling the graphics card so I haven't written off a custom loop yet. from what I can see on youtube they dont look difficult to install. they are just much more expensive.

@Pcbuilder123: Normally I am right with you, I typically trust air cooling for all my needs and have seen excellent results. My Xenon rarely tops 40c even when running dozens of aps an games simultaneously. That being said, I am looking at water cooling specifically because of the FX9000 series chips which clock in at 220W at stock speed. I am not confidant that an air cooler will be sufficient.


TekSyndicate used a nh-d14 on a 9590 :) 
July 16, 2014 10:19:49 PM



Passive coolers are a very bad idea. Mostly, people think it is okay to get a fully passive system, but that is not how it works, lol. A passive cooler is engineered to run with air flow around it, not absolutely nothing. Maybe for an a6 web browsing machine it might be okay, but nothing serious.
July 17, 2014 2:53:38 AM

DHFF said:
@ Skywere: From what you have explained its obvious a custom system would provide that because I could install multiple radiators that would provide more cooling.


More radiators provide more cooling potential, not more cooling. If a 240mm rad is enough, having five of them wont make a difference to the temperature of your chip. Common water-cooling to an extent is just displaced air-cooling, your still bound by ambient air temperature, the only difference is that water is a better conductor than copper heat pipes and radiators are bigger than your typical heatsink. Related to below.

DHFF said:
On the other hand I really dont know what kind of stress a 220W chip will put on a cooling system and I am nervous that a closed loop wont be enough.


220W, thats exactly what a 220W (TDP = Thermal Design Power = rough power consumption) chip is going to put on a cooling system. If a CPU consumes 220W, your going to get a bit less than 220W of heat coming out of it.
Water-cooling radiators are tested by the wattage they can deal with at certain fan RPM's (whatever fans you use might give different results though)

July 17, 2014 3:05:32 PM

Just to say, when the fx9xxx first came out, it was paired with a h80i equivalent CLC as the CPU cooler, but was a little expensive. I guess to cut the costs some as ppl who buy that chip plan on OC, yada yada yada, get their own cooler like h100i etc, so the stock CLC was pointless. Now the CPU is sold w/o a cooler for almost $100 less. Point is, a 240/280mm CLC will easily handle a 220w CPU.

What I think is funny is that the fx9's are just 8320's factory OC to 5GHz, so don't expect much OC beyond that.
July 17, 2014 3:31:08 PM

Rather unfair test. It's not so much AMD vrs Intel, its AMD vrs nVidea, I've seen benchmarks where an r-9 270 decimated a gtx 760, and the very next test on a different game, the gtx 760 blew the doors off a r9 280x. So its not fair to say one CPU is better than the other, when the gpus are in a biased scenario to begin with.
July 17, 2014 3:33:57 PM

@Pcbuilder123: good to know about the nh-d14, di they get good results out of it?
@manofchalk: thank you for the info. An yes I realized that a 220W chip gives off 220W, its fairly self explanatory, I simply dint know how much cooling I would need to keep it tame. For example the H100i has a 240mm radiator and I was unsure if that would be enough or if a custom system with larger or more radiators would be needed. From what Pcbuiler says about Techsyndicate using an air cooler and Karadjgne's reference to the 9000 series originally coming with H80i coolers. I am confidant about an H100i being more then enough for non overclocked use of the chip.
July 17, 2014 3:40:56 PM

They used to use an h100i but it was very loud because it was mashed against the fans, so they switched over to an nh-d14. They said it is nearly silent and identical performance (1-2 degrees hotter) and infinitely quiter. Temps around 65 degrees at 5.0ghz.
July 17, 2014 3:57:31 PM

the stock fans on a h100i are loud either way, good rad fans, just noisy as hell. If you want quiet performance from a h100i, dump the stock fans and get a couple Noctua NF-P12 PWM (same fan used on NH-D14) or NF-F12 PWM, set the h100i to extreme, then let the mobo control the fan speeds through bios/software. I did this with my h55 and from 2 feet away my pc is so silent, the only way I know it is running is the power/hdd led's are on. My overhead fan on slow is louder than my pc during regular usage.
July 18, 2014 6:37:24 AM

Yeah The Coirsair Stock fans for the H100i are rated at almost 38dB which is pretty crazy. If I get the H100i I might yank the fans and install them in a server at work where noise is not a concern.

EDIT: In regards to the nh-d14, I thinks all things considered equal I will just go with the H100i simply because the NH-D14 is a Godzilla of a cooler. I have never used one but I have seen a few in person and the clips looks very flimsy for a cooler that weighs almost 3lbs. I think the H100i would put far less physical strain on the motherboard and its honestly not that much more.

I usually prefer air coolers but I think I just sold myself on a closed loop system.
July 18, 2014 3:57:34 PM

Jfyi, the NH-D14 has one of the best built, best designed and sturdiest mounting system out of all towers. I personally prefer CLC's (not a fanboy btw) but if I did have to recommend a higher potential aircooler, it would be the D14.
July 18, 2014 8:51:06 PM

Well I will take your word for it. perhaps I am missing something but from what I saw it looked like the unit was being held in with clips. I feel much more secure with units that screw in like the Hyper 212.
July 18, 2014 9:20:54 PM

DHFF said:
Well I will take your word for it. perhaps I am missing something but from what I saw it looked like the unit was being held in with clips. I feel much more secure with units that screw in like the Hyper 212.


The nh-d14 is super, super secure Noctua also provides new clips if you upgrade to a new motherboard (to a new socket when it releases.

This is the system, it uses a back plate. Would the most respected fan/ one of the most respected air cooler manufacturers will use low quality clips? (no, lol)
July 18, 2014 9:25:08 PM

Fair enough, the back plate looks sturdy enough. I still dont know if I am brave enough to put that small tank on my motherboard :)  I think it would also scare everyone at work as this will be for my workstation. it spooked everyone the first time they saw me installing a Hyper 212 , this ting would cause heart attacks :D 
July 19, 2014 1:57:46 PM

I'm sure the first person to imagine slapping a supercharged blown big-block in a Chevy Vega had the same impression, but the results were nothing short of OMG. Once your co-workers get aload of your resulting output and temp capabilities, I think you'll have a 'cottage industry' in retro fitting their PC's with upgraded cooling solutions.
July 19, 2014 6:09:50 PM

This beast of a cooler (v8 gts) is infamous for cracking motherboards....
July 19, 2014 8:44:31 PM

Looks like you strapped a diesel engine to your motherboard :D 
July 19, 2014 8:54:29 PM

Whats laughable is while the V8 is a good cooler, its not as good as some coolers 1/2 its size-weight. It comes down to a LOT of show, and not near as much go...
July 19, 2014 9:43:08 PM

There are plenty of huge and very expensive air coolers but my favorite is still the 212. with a good pair of Noctuas equipped, that thing can handle quite a lot.
July 19, 2014 9:50:48 PM

Yes. The 212 can handle @180w which is most CPUs @4.4-4.5GHz, although by those speeds its close to max rpm so is starting to get loud.
July 19, 2014 9:59:42 PM

180W...
You know that a standard Core i7 has a stock TDP of 88W, a moderate overclock like 4.5Ghz that barely requires a voltage increase is not going to add 100W to its power consumption.

Use this formula, it will roughly tell you what power consumption (and heat output) to expect from a particular overclock.
OC Wattage = TDP * ( OC MHz / Stock MHz) * ( OC Vcore / Stock Vcore )^2
July 20, 2014 9:27:49 AM

If I'm reading that formula correctly, and doing the math right, a jump on my 3570k from 3.4 stock to 4.5 OC puts my wattage at 154. Using the same numbers but with the 88w of an i7 puts it at 178. Not knowing the exact voltages of of someone's i7OC is say its gotta be pretty close either way. It's that, or my math is screwed lol.
July 20, 2014 9:43:34 AM

Yes runs at 80-90W stock but there are many chips that go way over that. An FX-8350 for example runs at 125W stock. Wouldn't take much overclocking to exceed 180W. An i7-3820 for Sandy Bridge runs at 130W. Again it wont take much to push these chips tot he point where they would need a very robust cooling system.
July 20, 2014 2:23:34 PM

Yep, lol. For a 6300 a tx3 isnt bad either, 125tdp great for a small cooler for relatively small oc's.
July 20, 2014 8:22:46 PM

I guess that's one thing I like about CLC's, they start at like a h-55 and work up to a h-110 in stages. With most common aircoolers you start with a tx3 then the EVO then nh-d14. And its 125w, 180w, 240w. And most of the other coolers just don't compare in performance.
July 20, 2014 8:29:41 PM

Larger variety price and performance along with different thog yo suit your needs. Low end clc's tend to be not as good as high end air coolers (same price though).

Have you seen this, somebody clc blew up because of the cold weather:https://www.google.com/url?sa=t&source=web&rct=j&ei=_Ij...
July 20, 2014 10:08:09 PM

Thats is my recurring nightmare about liquid coolers. I am convinced that one day I would open my case and find my motherboard dripping in coolant.
July 20, 2014 11:11:39 PM

DHFF said:
Thats is my recurring nightmare about liquid coolers. I am convinced that one day I would open my case and find my motherboard dripping in coolant.


Haha, aside from budget constraints, in my top 3 reasons to not buy liquid coolers

CLC
Top 3 cons
1.No point in my budget rig
2.Better air coolers for same price that are quieter
3.Risks of water cooling

Top 3 pros
1.Performs slightly better for serious overclocks (high end ones like a corsair 110
2.Look pretty cool
3.If you have a cool room and good fans it should be relatively quiet.
July 21, 2014 6:52:25 AM

Thats what I keep coming back too, Even with liquid cooling, it still comes back to the fans. So I budget in $100 for a Corsair H100i, but then I have to budget in another $50 for a pair of Noctuas. IF I take those same two Noctuas and put them in a push pull on my 212EVO, I should get similar performance and I would be spending about $65 less.

Now yes If you are seriously overclocking you can build a custom loop with large radiators ect. but then you are talking hundreds of dollars so for within the $100 range is seems smarter to go with an air cooler.
July 21, 2014 1:58:56 PM

Push/pull on a 212 does nothing but raise vrm temps and add more fan noise, jfyi, and when replacing the stock fan you need to be careful about cfm, if its too much greater than stock, you'll actually get worse performance as the heat from the fins does not have sufficient time to transfer tothe air passing over them.
July 21, 2014 6:05:18 PM

Adding more fan noise I can understand. but I am afraid I don't follow you on your last statement. A rapid flow of air will only increase heat transference. The testing team here at Toms demonstrated this in their CPU cooler reviews, the replaced the stock fan on each model with 2500RPM fans an in each case a lower temp was reported.
July 21, 2014 7:07:47 PM

Push pull only decreases temperatures by 2-3 degrees.


This is on an underclocked i5 3570k btw.


July 21, 2014 7:26:32 PM

I would recommend NOT buying an fx9590. there is no reason to at all and DEFINITELY not worth the trouble.
July 21, 2014 7:36:45 PM

Yep, teksyndicate said there is no place in the market for it. AMD just wanted to impress people who don't know much about cpu architectures and for those who had compatible motherboards.
July 21, 2014 8:17:05 PM

Rapid flow of air does increase heat transference, upto a point, and once past that point it will slowly start a reversal. If the tower has a thinner width, what happens under very high cfm is the air blowsthrough so fast it picks up a lot less of the heat. Slightly slower air will absorb more heat before exiting the planes.

As far as the VRMs go, the air pushed into the tower has 'bleed' around the sides. It's this air that wafts over the VRMs and other components next to the CPU. Adding a pull fan, you draw that air through, so you don't get the bleed. It's one of the same situations that CLC's suffer from, since the CPU fan is located on the rad,
July 22, 2014 3:44:53 AM

I can see your point on the pull fan, that makes sense and I totally agree that liquid cooling loops subtract a portion of airflow over the RAM,chipset ect.. I know of a number of guys with loops that put intake fans on the bottom of the case or on the side panel for this reason.

As for the the heat sink fan blowing so fast that thermal transference breaks down, I dont think that is a realistic concern. Fans upwards of 3500RPM have been mounted on coolers with positive effects. Much faster then that most people do no use because noise becomes a factor. If you have research that shows just how fast the fan would need to move before the heat transfer breaks down, I would be very interested in reading it because now you have me curious :) 

EDIT: I did some research on this . It is true that as the air moves faster it will be less efficient at absorbing the heat however the on the other hand as the air velocity increases, you are increasing the volume of air moving over the heat pipes so the overall amount of heat dissipated increases. So yes it becomes less efficient but you will never notice this efficiency loss because the increased volume will result in lower temps.
July 22, 2014 8:53:59 PM

That makes sense.
July 22, 2014 9:51:10 PM

+Karadjgne
As you are a power supply expert, what do you think of the xfx550 watt power supply? I am planning on buying that next month (as a 14 year old took me a while to save up), followed by a 1080p 24" asus ips monitor followed by an r9 280 or similarly performing nvida maxwell 8 series card. Is it powerful and good quality?
July 23, 2014 4:13:06 AM

Here's the gimmick on psus. It's all about quality. The XFX psus are built in a Seasonic platform, andare in most opinions about as good as you can get. The XFX 550w has a very high 12v output, has excellent over-protections and imho is worth more than its price. It's one of a few 550w psus powerful and stable enough to power a 780ti with an OC pc.You really can't do better for the price, its an outstanding psu. If 550 makes you nervous still, the Antec 620m HCG, Seasonic m12II 620, or XFX650 are also excellent psus.
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