watercooling cpu and 2x gpu's, 1 loop or 2 ?

Unforgiven · 09-20-2005, 02:59 PM

Hi all,

I have an FX-55 and 2 x 7800 GTX's in SLi, currently I have a storm block, pa160 rad and mcw655 pump cooling the FX55.

I now want to cool the 2 gpus, I have room to add a separate loop with 120mm rad/pump/2 gpu blocks to cool these 2 gpus or should I just add the 2x gpu's to the fx55 loop?

If I should run 2 separate loops should I use the pa 160 on the cpu or 2xgpus as the gpus will be putting out more heat than the single cpu?
Any help much appreciated.

jaydee · 09-20-2005, 11:11 PM

I would try it with one loop first. If that dosn't satisfy then go two.

Long Haired Git · 09-21-2005, 01:44 AM

No PA160 PQ graph
No PA160 CW graph
What fan(s) on the PA160?
No GPU block mentioned, and even if, is there a PQ graph for it? CW graph?

Also, what is your aim? Absolute performance? Silence? Bang for buck? Best of both worlds?

Budget?

Best solution is obviously a dedicated pump, radiator and block for each peice of equipment. However that's expensive, space-intensive, heavy and could even be "too noisy" for you.
If you want silence, then the pump can cope with all three blocks, and the radiator will cope too, but you're temps are likely to take a "noticeable" hit.

I'd model in approximator, but have no data for PA160 nor any GPU blocks, so no point.

However, lets assume right now your CPU is 80W and your GPUs are 40W each. If your coolant has to rise to X degrees above ambient now in order for the radiator to be able to disperse the 80W, then it will need to rise to 2X above ambient to rid the extra 80W from the GPUs. This increase, being X, will then be added to your current CPU temp.
Next, flow rates will decline, and so the effeciency of the rad and GPU will decline. This would typically acount for "a couple" of degrees.

So, sticking with the PA160 would result in probably 5 to 8 degrees hotter, as a big wild guess. I would say "done!" for the silence and the performance, but some would not be happy with that compromise.

So, what's YOUR poison?

ricecrispi · 09-21-2005, 01:48 AM

Do you really need two 7800gtx in SLI? One should be enough unless you are try to run at something larger than 23 inch screen.

One 7800gtx is already enough, one beats 6800 ultra in SLI and one 6800 ultra is more than enough for every game........

Marci · 09-21-2005, 04:22 AM

No-one NEEDS half of whats in their PC.... u should know that by now fella....

Long Haired Git · 09-21-2005, 04:49 AM

Marci - got some approx PQ figures or CW figures I can have?

Marci · 09-21-2005, 05:58 AM

C/W figures - http://www.thermochill.com/pa160.php

Quote:

Tricod @ 5.0v => 0.075 c/w (est: 10dBA, 23cfm)*
Tricod @ 12.0v => 0.044 c/w (est: 22dBA, 45cfm)*
Panaflo L1A @ 12.0v => 0.031 c/w (est: 30dBA, 69cfm) *
Panaflo M1A @ 12.0v => 0.026 c/w **
Panaflo H1A @ 12.0v => 0.022 c/w (est: 41dBA, 104cfm)*
Panaflo H1A @ 16.0v => 0.020 c/w (est: 48dBA, 130cfm)*

Papst 4312L @ 12.0v => 0.038 C/W
Papst 4312L @ 7.0v => 0.051 C/W
Papst 4312L @ 5.0v => 0.062 C/W

Noiseblocker XS1 @ 12.0v => 0.050 C/W
Noiseblocker XS1 @ 7.0v => 0.065 C/W
Noiseblocker XS1 @ 5.0v => 0.078 C/W

XinRuiLian RDL1225S @ 12.0v => 0.047 C/W
XinRuiLian RDL1225S @ 7.0v => 0.060 C/W
XinRuiLian RDL1225S @ 5.0v => 0.074 C/W

PQ Curves - none done as yet that I know of...

Long Haired Git · 09-22-2005, 07:09 AM

Ta.
For the approximator I'll just stick its PQ graph as half way between the 120.1 and the 120.2.
Ditto, the shape of the C/W chart will be a mix of the two, with a fudge to get it to pass through the points for the tricods.

Marci · 09-22-2005, 07:45 AM

I do have air resistance curves in the pipeline. Need to speak to Cathar about liquid resistance curves etc as to whether he has facilities/time to draw some up or not...

Unforgiven · 09-22-2005, 11:28 AM

Quote:

Originally Posted by ricecrispi

Do you really need two 7800gtx in SLI? One should be enough unless you are try to run at something larger than 23 inch screen.

One 7800gtx is already enough, one beats 6800 ultra in SLI and one 6800 ultra is more than enough for every game........

I couldn't think of a reason not to

I'll try one loop, see what the temps are, then go to two loops, compare the two and if the benefits of two loops are good enough I'll keep it, if not I can always sell the extra pump and rad.

I know it's a bit trial and error but it's the way I work ;-)

Dr_Strangelove · 12-11-2005, 11:58 PM

So what is the verdict? Do you have it running? Results?

billbartuska · 12-12-2005, 11:51 AM

Quote:

Originally Posted by Marci

I do have air resistance curves in the pipeline.

EURIKA!

09-20-2005, 02:59 PM	#1
Unforgiven Cooling Neophyte Join Date: Sep 2005 Location: UK Posts: 2	watercooling cpu and 2x gpu's, 1 loop or 2 ? Hi all, I have an FX-55 and 2 x 7800 GTX's in SLi, currently I have a storm block, pa160 rad and mcw655 pump cooling the FX55. I now want to cool the 2 gpus, I have room to add a separate loop with 120mm rad/pump/2 gpu blocks to cool these 2 gpus or should I just add the 2x gpu's to the fx55 loop? If I should run 2 separate loops should I use the pa 160 on the cpu or 2xgpus as the gpus will be putting out more heat than the single cpu? Any help much appreciated.

09-21-2005, 01:44 AM	#3
Long Haired Git Cooling Savant Join Date: Jan 2003 Location: Sydney, Oz Posts: 336	No PA160 PQ graph No PA160 CW graph What fan(s) on the PA160? No GPU block mentioned, and even if, is there a PQ graph for it? CW graph? Also, what is your aim? Absolute performance? Silence? Bang for buck? Best of both worlds? Budget? Best solution is obviously a dedicated pump, radiator and block for each peice of equipment. However that's expensive, space-intensive, heavy and could even be "too noisy" for you. If you want silence, then the pump can cope with all three blocks, and the radiator will cope too, but you're temps are likely to take a "noticeable" hit. I'd model in approximator, but have no data for PA160 nor any GPU blocks, so no point. However, lets assume right now your CPU is 80W and your GPUs are 40W each. If your coolant has to rise to X degrees above ambient now in order for the radiator to be able to disperse the 80W, then it will need to rise to 2X above ambient to rid the extra 80W from the GPUs. This increase, being X, will then be added to your current CPU temp. Next, flow rates will decline, and so the effeciency of the rad and GPU will decline. This would typically acount for "a couple" of degrees. So, sticking with the PA160 would result in probably 5 to 8 degrees hotter, as a big wild guess. I would say "done!" for the silence and the performance, but some would not be happy with that compromise. So, what's YOUR poison? __________________ Long Haired Git "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford) My Rig, in all its glory, can be seen best here AMD XP1600 @ 1530 Mhz \| Soyo Dragon + \| 256 Mb PC2700 DDRAM \| 2 x 40 Gb 7200rpm in Raid-0 \| Maze 2, eheim 1250, dual heater cores! \| Full specifications (PCDB)

09-21-2005, 04:22 AM	#5
Marci Cooling Savant Join Date: May 2003 Location: Wakefield, West Yorkshire, UK Posts: 486	No-one NEEDS half of whats in their PC.... u should know that by now fella.... __________________ www.minimotosidecars.org / www.thermochill.com / www.themusiccollective.co.uk

09-21-2005, 04:49 AM	#6
Long Haired Git Cooling Savant Join Date: Jan 2003 Location: Sydney, Oz Posts: 336	Marci - got some approx PQ figures or CW figures I can have? __________________ Long Haired Git "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford) My Rig, in all its glory, can be seen best here AMD XP1600 @ 1530 Mhz \| Soyo Dragon + \| 256 Mb PC2700 DDRAM \| 2 x 40 Gb 7200rpm in Raid-0 \| Maze 2, eheim 1250, dual heater cores! \| Full specifications (PCDB)

09-22-2005, 07:09 AM	#8
Long Haired Git Cooling Savant Join Date: Jan 2003 Location: Sydney, Oz Posts: 336	Ta. For the approximator I'll just stick its PQ graph as half way between the 120.1 and the 120.2. Ditto, the shape of the C/W chart will be a mix of the two, with a fudge to get it to pass through the points for the tricods. __________________ Long Haired Git "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford) My Rig, in all its glory, can be seen best here AMD XP1600 @ 1530 Mhz \| Soyo Dragon + \| 256 Mb PC2700 DDRAM \| 2 x 40 Gb 7200rpm in Raid-0 \| Maze 2, eheim 1250, dual heater cores! \| Full specifications (PCDB)

09-20-2005, 11:11 PM	#2
jaydee Put up or Shut Up Join Date: Dec 2001 Location: Spokane WA Posts: 6,506	I would try it with one loop first. If that dosn't satisfy then go two.

09-21-2005, 01:48 AM	#4
ricecrispi Cooling Savant Join Date: Jul 2005 Location: california Posts: 429	Do you really need two 7800gtx in SLI? One should be enough unless you are try to run at something larger than 23 inch screen. One 7800gtx is already enough, one beats 6800 ultra in SLI and one 6800 ultra is more than enough for every game........

09-22-2005, 07:45 AM	#9
Marci Cooling Savant Join Date: May 2003 Location: Wakefield, West Yorkshire, UK Posts: 486	I do have air resistance curves in the pipeline. Need to speak to Cathar about liquid resistance curves etc as to whether he has facilities/time to draw some up or not... __________________ www.minimotosidecars.org / www.thermochill.com / www.themusiccollective.co.uk

12-11-2005, 11:58 PM	#11
Dr_Strangelove Cooling Neophyte Join Date: Dec 2005 Location: Chicago Posts: 79	Re: watercooling cpu and 2x gpu's, 1 loop or 2 ? So what is the verdict? Do you have it running? Results?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)