Dual GPU OC and Cooling

H

HighYield

Gawd
Joined
Feb 2, 2008
Messages
944
I just set up my first dual gpu folding boxen and had two questions to put out for everyone.

1. How do you overclock both gpus at the same time? I think the EVGA tool and the nvidia performance tool only do the first gpu (at least that is what the ppd looks like to me). I've had issues with riva tuner on a different 64 bit vista box so I would prefer not to use it, but if it is the only way I'll try it again.

2. I used 2 8800GTs the (cheap ones that don't vent the heat out of the case). When there was one in the case the temps were fine, but now that there are two it has totally overloaded my cooling solution. It's a damn nuclear furnace in fact. How are you guys cooling your dual gpu systems? I had to pull the sides off the case otherwise I think it would have gotten so hot the compents would have been damaged (GPUs were heading past 80C quckly) With the side pannenls off case the GPUs are back down to the mid 60s. As I have 2 curious 5 year olds that really like my computers, I would like to keep the sides on to keep them from getting hurt (and keep the boxen folding nice and steady).

Is the dual GPU set up worth it? You bet. The boxen is [email protected] with 2 gig ram on 64 bit vista with AC on.

Here are some quick and dirty ppd (last 3 frames in fahmon)
1GPU
1907 p2653 SMP
1668 p2665 SMP
5316 GPU1 (8800GT OC)
Total 8891 ppd

2GPU
1676 p2653 SMP
1628 p2665 SMP
5184 GPU1 (8800GT OC)
4823 GPU2 (8800GT stock)
Total 13311 ppd
Not bad for just one boxen. I'll be able to use it as a space heater in the winter ;)

 
You can do a couple things for those cards. If you've got any modding skills you could cut a 120mm hole out for a fan over the cards in the side panel. Or you can look at maybe going with an antec super cyclone. My buddy just put one in his that is running a single 4850 and he said it dropped his gpu temps about 5c.

 
Imitation said:
You can do a couple things for those cards. If you've got any modding skills you could cut a 120mm hole out for a fan over the cards in the side panel. Or you can look at maybe going with an antec super cyclone. My buddy just put one in his that is running a single 4850 and he said it dropped his gpu temps about 5c.

Click to expand...
DSC00313.jpg


This is what I did, dropped the temps 10-15 C easy. I'm planning on getting hold of another 120mm fan and cutting a hole for it.

 
In order to be able to OC (I used Rivatuner, EVGA Precision only sees 1 card) the second card you have to extend the windows desktop to the second card. In Vista you need a second monitor or 2nd cable (VGA) to your first monitor. I've heard you don't have to have a monitor hooked up in XP, but on my system it wouldn't work (Rivatuner couldn't see the second card) until I hooked it up (I used a VGA cable from the DVI/VGA dongle on 2nd card to te second port (VGA) on my monitor)

For the heat (and it IS alot more with a 2nd card) I just left the side cover off the case. If it gets TOO hot I'll put a fan blowing in there.

Luck!

 
Wait!....you guys use cases? No no no no no no no no....
Hell the cost of two mediocre cases will get you another 8800GT!

Papa John's pizza boxen are the only proper substrate.
(Pepperoni grease is rumored to significantly improve OC)

One good box fan can cool a half dozen folding pizza-boxen with as many GPUs as you can afford.

This is [H]ard DC....cases....sheesh, ;)
 
If I was home I would post the pic of my boxen on the plastic shelf. I dont even mess with boxen for most of my rigs. :)
 
Keeping the case on is good for keeping little kid's fingers out. I moved the open case next to the wall. That should discourage the casual poking of the cpu fan ;) and keep everything cool.

relic is right. It would be a lot cooler without the case in the first place. Maybe my next build will be with cardboard.
 
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