Well I just got my new SLI dual 8800GTX machine and I am a bit worried about the temperature they are running at. Sitting idle the GPU's seem to run at about 65 celcius and when running game they can get up to 75-85, depending on the game. I am a little concerned about those temperatures, is that high for these graphics cards or is that relatively normal?
Considering that these cards run as hot as my car which develops block warping at around 125C that a valid concern. All I can say is warranty. These will likely be the hottest cards produces for some time. I sure the second gen card will address power and temp issues.
I'd say that your cards are running a little hot but by no means are they bad. Since they are in a SLi configuration you must make sure you have good airflow cause you now have twice the heat to deal with. Airflow is key to keeping temps lower.
As far as how hot they run well just check out a X1900XTX and compare, they easily run intos the 80s and even touch the 90s, those would be the hottest cards on the market. Even the X1950XTX isnt much better, nvidia's last 2 generations of graphic cards run cooler since there was less power draw than X1950XTXs, while the 8800GTX/S experienced a mild increase in temperature from the 7 series they still are 75% of the time will run cooler than a X1950XTX.
Your cards are fine but they are running a little warm for typical nvidia graphic cards which would be expected since your running them in SLi. Make sure you have good airflow and see if that helps at all..
When i first installed my two eVGA 8800gtx's my temperatures were 65-68C idle and load 75-78C. What i did first i used two 90mm TT fans and placed them so that they are blowing into the cards. I have my case open now which is not a big deal. The temps droped to 56-58C idle and 70-72C Load.
Secondly I installed nTune and used the software to adjust the fan speed. http://www.nvidia.com/object/ntune_5.05.18.00.html
Here is a picture where to adjust the fan speed. My temps are 50C idle and 56C load. The only draw back is everytime i restart my PC i have to apply these setting so that the fan speed runs at 99%
Click - Adjust GPU Settings
Click - Direct Fan Control (Try applying the fan settings till it locks at 99%)
Make sure that you go on top of the menu (VIEW) and make sure to click (ADVANCE) so that the Adjust GPU Settings appears.
You are correct. With cases that have front/rear fans moving a lot of air, you'll get better performance with the case completely closed. It forces the air to run over the components instead of just sucking air from your room into the rear fans.