With the graphics card installed in a closed case, the temperature of the GPU at idle was 56C. With the Real-Time High Dynamic Range Image Based Lighting (rthdribl) demo running in an 800x600 window, the GPU reached a peak temperature of 95C with the room temperature at 22.7C / 73F. As a side note, I also conducted the same series of tests with the room temperature at 78F where the GPU temperature topped out at 100C.
Using NVIDIA's nTune, I started to increase the fan speed in increments of 10% and recorded the GPU, memory, and ambient temperatures as reported by Everest Ultimate Edition. The results are shown in the following graph.
A second test was then conducted to determine the point at which I could begin to hear the fan with all the case fans powered down and with all the case fans running at 75%. The results of this test are shown by the shaded area in the graph, which is labeled as the "Optimal Fan Noise to Cooling Zone." At 45%, the fan noise is hardly noticeable and only begins to become noticeable at 50%.
Although this information was collected using my PC, the results would indicate that with a properly ventilated case, an aftermarket cooler is not a requirement in order to adequately cool the GeForce 8800 GT. NVIDIA's engineers devised a cooling solution whereby all of the boards components are behind a metal faceplate.
