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Topic: Heat dissipation (Read 1464 times)

sr. member
Activity: 413
Merit: 250
July 22, 2011, 09:13:29 AM
#7
This is just a rehash of what others are saying but I run dual 5870's in a closed case. Antec 900.

Now first, I have both front intake fans on high, the top exhuasting, the PSU exhausting, and the rear exaust fan on high. I then put in a 150ish CFM fan into the side, it's a double thick one and is always on high.

This computer sits directly front of the AC, at 900/300 clock speeds my gpu's are around 70c. I won't push them higher becuase I've already had 1 die.

You should realistically be running an open air rig with those style of cards, then your box fan on the "front" would achieve a lot as it's moving ALL the air across the pc. As the msi coolers you linked are terrible.

If you want to get fancy, I'd put one big piece of cardboard on the side of yoru case. Mount a 120mm fan over both of your gpus for intake, then towards the front of your case on the cardboard mount 2 120's for sucking the hot air out. You might be able to lower the temps with enough push/pull effect.


Also, how hot is your room?
hero member
Activity: 770
Merit: 502
July 22, 2011, 08:44:21 AM
#6
To apply TIM, don't spread it. Depending if your GPU is tiny, use half size of a pea drop. Set the HS directly in place, it is kinda tricky, carefully give pressure to the HS pushing down, let the HS do the spreading as this for sure does not create any air pockets, then secure it with the screws. After the screws are tightened, give it a little more push pressure, be very careful as not to slip your hand on a capacitor etc, and be careful of back of the gfx card in this process. As the GPU heats up, this process will also help spread the TIM itself in time. TIM=Thermal Interface Material. This goes the same for CPU's, don't spread TIM's. Use push down pressure of the HS.

Good luck.
member
Activity: 98
Merit: 11
July 21, 2011, 12:53:14 PM
#5
I've come to realize that GPU temps are dependent on a huge array of factors - it's difficult to optimize all of them while retaining performance.

I have 4x 6950's, they were all running ~85-90C in a case with exceptional airflow.  I now have them 'open air' with a ridiculous ventilation system setup to push cold air from an adjacent room directly onto the cards, and I'm getting between 75-85C now.

If your cards are the 'two fan' variety, the only 'intake' is the fans themselves.  They will simply expel hot air everywhere, which generally rolls around and gets sucked back into the fans.  This is a fatal flaw of these cooler types.  Blowing a box fan, etc directly at the cards will make no difference, and may infact increase temperatures, as you're fighting against the exhaust of the cooler fans.

What flags are you using to run your miner?  I've found a drastic difference between -f10 and -f30 on my cards with poclbm for example;  With -f10, my GPU runs at 99% load and temps raise at least 5C.  With -f30, I run at 98% and cooler.  I lose about 5mhash/s / card at -f30 (the default).

MSI's website blows and I can't see pics of the card for some reason, so I can't offer more specific suggestions.

For a closed card with turbine fan (reference cooler), intake is at the rear of the card and exhaust is out the back of your case - these are very easy to direct air into.

Dual-fan or non-reference designs with big honkin' heatpipes, etc, are harder as you need to try to prevent the expelled hot air from being recirculated through the card.

If you've re-applied the thermal paste properly (very thin layer spread over the surface of the GPU), and you're getting 83C at full load, you're actually not doing too badly.  These cards can usually take the pain, and don't thermal-throttle until 100C+

I'd do more experimenting before spending a bunch of money on aftermarket coolers.  Don't get discouraged, it's really not easy to find the right balance.




Great advice there. I've been having similar issues with the non-reference cards and the only solution I've found (when running more than two cards per box) is to run this rather insane delta fan with 240cfm. Luckily my server rack isn't in my living room anymore.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835213001
full member
Activity: 196
Merit: 100
July 21, 2011, 12:37:44 PM
#4
I've come to realize that GPU temps are dependent on a huge array of factors - it's difficult to optimize all of them while retaining performance.

I have 4x 6950's, they were all running ~85-90C in a case with exceptional airflow.  I now have them 'open air' with a ridiculous ventilation system setup to push cold air from an adjacent room directly onto the cards, and I'm getting between 75-85C now.

If your cards are the 'two fan' variety, the only 'intake' is the fans themselves.  They will simply expel hot air everywhere, which generally rolls around and gets sucked back into the fans.  This is a fatal flaw of these cooler types.  Blowing a box fan, etc directly at the cards will make no difference, and may infact increase temperatures, as you're fighting against the exhaust of the cooler fans.

What flags are you using to run your miner?  I've found a drastic difference between -f10 and -f30 on my cards with poclbm for example;  With -f10, my GPU runs at 99% load and temps raise at least 5C.  With -f30, I run at 98% and cooler.  I lose about 5mhash/s / card at -f30 (the default).

MSI's website blows and I can't see pics of the card for some reason, so I can't offer more specific suggestions.

For a closed card with turbine fan (reference cooler), intake is at the rear of the card and exhaust is out the back of your case - these are very easy to direct air into.

Dual-fan or non-reference designs with big honkin' heatpipes, etc, are harder as you need to try to prevent the expelled hot air from being recirculated through the card.

If you've re-applied the thermal paste properly (very thin layer spread over the surface of the GPU), and you're getting 83C at full load, you're actually not doing too badly.  These cards can usually take the pain, and don't thermal-throttle until 100C+

I'd do more experimenting before spending a bunch of money on aftermarket coolers.  Don't get discouraged, it's really not easy to find the right balance.

donator
Activity: 2352
Merit: 1060
between a rock and a block!
July 21, 2011, 10:49:41 AM
#3
If you want the case closed, you have no choice but to add high CFM fans to remove the heat.
Side fan/s to bring room temp air in and at least same CFM to take the air out through front, top, whatever.
the temp inside the case will rise right in the area where the cards are.  if you move the air, the temp should be under "control"
hero member
Activity: 770
Merit: 502
July 21, 2011, 10:37:25 AM
#2
First things first. It is a Graphics processing unit and not a Central processing unit. GPU, not CPU.

To properly clean your GPU & HS, use 91% isopropyl alcohol, can be found at walgreens or CVS, thats if you are in the US. Or grab yourself some arctic clean can be found at places like newegg or some retailer, use lint free material like coffee filters.

1. IC diamond is known to scratch surfaces. Look into Shin Etsu.

2. Very good after market cooler

2b. Probably best bet is a tech station with a few 120mm or 140mm fans on the graphics card.

vip
Activity: 812
Merit: 1000
13
July 21, 2011, 10:21:21 AM
#1
Heat dissipation
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