Eximo :
Having tried pretty much all of the solutions out there in various builds I can say that even a thin 120mm is enough for a single GPU even after overclocking. Really reduces the maximum temperature and gets it out of the case, so they are more then a gimmick. Expensive though.
1. That is in conflict with all available published lab testing.
It is plainly clear that 1 x 120mm is not quite up to "design targets". Easiest way to look at it is this. If it takes a H100i to do almost as good a job as an air cooler (i.e Noctua NH-D14 / Cryorig R1) with 2 x 120mm @ 2700 rpm for a CPU that generates only 84 - 135 watts overclocked, then how can we expect half that radiator area to handle GPUs with 1.5 to 2.0 times the wattage ?
In a well ventilated case, one should not expect any higher GPU overclocks than air cooled models. I have two Asus DCII 780s w/ EK Water Blocks and a 26% OC. A subsequent build w/ two MSI Gaming 780's (air cooled) did 27%. Obviously, heat is not a limiting factor here. Although, it must be said that using a non reference PCB with a beefed up VRM is a distinct advantage here which reference cards and even some non reference cards (i.e. EVGA SC which has no reference cooler but reference quality VRM) don't have. Taking the data from actual laboratory testing from martinsliquidlab .... "Busting out the science behind liquid cooling!"
https://martinsliquidlab.wordpress.com/2012/05/01/alphacool-nexxxos-st30-360-radiator/4/
Here we see that at 1400 rpm the 30mm thick Alphacool ST30 is able to dissipate 199 watts, 242 at 1800 rpm. Since the main reason to water cool these days is sound reduction, since performance gains are minimal, most folks will use 1250 rpm fans and keep them running below 850 rpm.
But even using the Swiftech's 1800 rpm fans @ 1800 rpm, that 242 watts for a 360mm rad works out to just 81 watts per 120mm.... just enough for a stock 4690k ... and no where near enough for a 970, 980, 980 Ti or the hotter running R9 series. Most 970's (Gigabyte's draws way more power then the competition) pull over 200 watts. All data below from Techpowerup for MSI cards, Gigabyte in ( ) when available
980 Ti = 279 - 281 watts (293 - 359)
980 = 205 - 207 watts
970 = 192 - 213 watts
MSI Afterburner, if memory serves, allows the following increase in Power Limit via afterburner
970 = 110%
980 = 122%
980 Ti = 120%
That makes the overclocked numbers ...
980 Ti =308 - 311 watts (322 - 395)
980 = 250 - 253 watts
970 = 230 - 256 watts
So at 1800 rpm, the 1 x 120mm delivers just 81 watts of cooling but we only expect the radiator fins too provide about 60% of the cooling for the following reasons:
-This are peak not average loads
-Additional cooling is accomplished by radiation from the block surfaces, tubing, fittings and even the radiator shroud surface (which is not measured nor included in the test data).
So taking the overclocked numbers from above x 60%
We need the rad to handle about 138 watts (230 x 60%) for the 970 and 1 x 120mm gives us just 59% of that.
We need the rad to handle about 150 watts (250 x 60%) for the 980 and 1 x 120mm gives us just 54% of that.
We need the rad to handle about 185 watts (308 x 60%) for the 980 Ti and 1 x 120mm gives us just 44% of that.
BTW, Delta T is not the difference between the GPU temp and anything... Delta T is the difference between the ambient air and the coolant. With a typical 80F (27C) indoor summer temp, this means your coolant w/ delta T of 10 will top out at 37. In the above instances, we are looking at 17 - 23C delta T. So at 27 C (80F) ambient, coolant temps are as high as 50C (122F) instead of 37C. Your GPU will be significantly hotter. The efficiency of the heat transfer is directly proportional to the delta T between coolant and GPU. So say you have a moderate load game playing and GPU temps are at 63C .... the heat transfer rate (GPU => Coolant) will be only 13C, about half as effective as it would be with the 10C Delta T coolant temp (26C).
And that's at a relatively noisy 1800 rpm. At 1250 rpm, still a bit of noise but bearable if using speakers. The 1 x 120mm gives just 60 watts of cooling (75%) and at a silent 850 rpm, just 43 watts (50%) .
On our 780 SLI rig, when coolant temps are 33C, the GPU runs at 39C (5 x 140mm of rad w/ 10 rad fans and 5 case fans) at 1200 rpm and 44C at 850 rpm which is where I have them set to not go any faster. The VRM however, even with the best water block for VRM temps is at 59C. We are pumping about 1.5 gpm while testing (max is 2.25) ... the CLCs do just 0.11 gpm.
Where CLC type water cooling typically fails is in VRM cooling.
As you can see above the EVGA Hydrocopper runs 30C above the EK. At 63 above say a 27C ambient, that's 90C ... the Hydrocopper doesn't do well but at least it's a full cover WB, which the CLC solutions are not. You may have GPU temps in the mid to high 60s even but your OC will likely be limited by your VRM temps rather than your GPU temp here.
In short ....
- I don't know that the single 120/140mm fan is capable of transferring enough heat to actually lower GPU temps.
- The VRM remains air cooled and may or may not do as well a job as the original equipment, especially w/ the small 80mm fan
- Coolant temps will be high
- Noise reduction, again the one area where water cooling can have a significant impact, is not accomplished due to the high speed fans.
2. Not sure what you mean by "getting [the air] out of the case" but if you have the radiator fans exhausting air from the case, you have installed it contrary to Swiftech's recommendations (as well as Corsair and every other water cooling manufacturer as far as I have seen). The air will get out of the case quite quickly, w/ proper fan orientation it will be force air thru the rad, into the case and right out the rear grille. We utilize 6 thermal sensors (0.1C accuracy) on the test rig and the fog machine testing gives a great picture of air flow. There is zero concern about the air exiting the radiator heating up inside components as it is immediately exhausted before it gets there.
3. Water cooling modern GPUs does not generally result in increased performance, as long as you have adequate case ventilation. At least, on nVidia's side anyway, I have not been able to do any better than on air since the 7xx series. The reason is that nVidia has, both physically and legally with their vendors, limited what is possible to do voltage / power wise
The main reason to WC GPUs nowadays, assuming you are not facing indoor temps much above 85C, is to reduce noise . Though the higher end cards can push the thermal limits, especially in SLI configs where a fan on the back of the HD cages blowing air between the cards is recommended, I haven't had any throttling occur.
4. I agree that the Swiftech H240-X option is far superior to CLCs and just about ideal for a 970 / CPU loop. Let's take that 135 watts for the C'd CPU and 230 for the OC'd 970. With the 60% factored in that's 219 watts of rad cooling needed. You can d/l martins data extrapolated out for every rad he's tested here:
http://www.overclock.net/t/1457426/radiator-size-estimator
Looking at the Swiftech file, at the fan's rated speed of 1800 rpm, you get 98 watts per 140mm and 119 in push / pull
So 98 x 2 = 196 watts or 89% of what ya need for delta T of 10C .... Delta T would be 11.2C. You can mount one extra fan in pull (can't install fan on reservoir side) which would give you 98 + 119 or 217 watts or 99%. I begged them to do a H340-X but no luck. That would easily allow a CPU / GPU loop w/ any single GPU card and most cases that fit 2 x 140 also fit 3 x 140mm. SLI / CF would then easily be accommodated by adding an extra radiator in front or bottom.
rubix_1011 :
Not sure I follow what you're saying. This is about a closed loop cooler on a GPU, not on a CPU. A full cover GPU block is around $120, correct, but you would still require pump, radiator, tubing, fittings, etc. While the cost of closed loop coolers is attractive, their performance is not.
The term 'you get what you pay for' applies here.
H240-X ($150) + 970 water block ($120) = $270.
$120 GPU CLC + $110 CPU CLC = $230.
The 17% cost premium gets you:
a) All copper components instead of alum / copper mix
b) No galvanic corrosion concern
c) Reservoir
d) Ability to expand loop
e) 1.0 gpm pump instead of two 0.11 gpm pumps
f) Much quieter fans
g) Huge leap in performance
h) PWM fan PCB / controller
Edit: Forgot, you'll need to buy two fittings for about $3 each for WB.
Edit 2 : If responding I'm sure many following the thread would ask that ya don 't quote the entire post so as not to make reading subsequent posts cumbersome to read . There was a lot of info to present and hopefully, it will be helpful to some.... but reading or better said scrolling past it 3, 4 , 5 times can be burdensome
After hitting reply, you can edit / remove less relevant parts.
Facebook
Twitter
Instagram