How I fixed my nVidia System Sentinel low power warning

[ahurtt]

I have an Asus A8N-SLI Deluxe motherboard with 2 PCI express BFG 6600GT OC cards and an OCZ Modstream 450 Watt PSU. Despite the fact that the power supply was more than adequate (according to recommendations in the motherboard manual) for a 2x 6600GT rig, I still was getting the nVidia System Sentinel warning that my video card was being clocked down due to low power while I was playing 3d games such as BF 2, CS:S, etc. . .I hooked up a multimeter and monitored the voltage while playing under load and the rails were rock solid steady. So I ruled out the PSU as the problem. I monitored Temperature, Voltage, Core speed, memory speed, and frames/sec using the tweaking utility called RivaTuner and I noticed one consistent thing. . .the temperature of the video card was getting to be what I would consider much too high. After playing 15-30 minutes, depending on the amount of stress/action going on in the game, the temp would creep up to 91-93 degrees. Then, shortly after reaching this temp, maybe right before the temp would hit 94, I would begin to get some current dips (shown on the screen display by RivaTuner but not on the multimeter) the card would clock down and the system sentinel would pop up. I could mitigate the problem by clocking down the video cards to their default spec speeds (the BFG's come factory overclocked by 25MHz for core and 50MHz for memory) which would let me play a while longer longer but eventually the temp would creep up and it would happen again. So I concluded that the problem was heat related. I got a can of compressed air and I examined the fins on the video card heat sink. I noticed there were small dust deposits building up in the openings of the fins. Not a lot. . .just a little. So I gave them a good blowing out with the compressed air can. The problem has not happened again since then even running with the out of the box overclock speeds. The cards do still get hotter than I would like to see. . .around 85-87 degrees, but apparently that little 5-8 degree temperature drop has solved my problem. So the lesson here is, keep those cooling fins clean and free of dust. Even though I have 5 case fans it was still overheating before I cleaned the video card heatsinks is the conclusion I have drawn. And it didn't take much dust on the video card to cause problems. Hope this helps somebody. I was about to RMA the video cards. I may consider replacing the stock heatsinks on these with some better aftermarket parts.

 

[eplebnista]

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