Hi, I've recently bought an NVidia 6800 Ultra which intermitently freezes during 3DMark05. The freezing causes everything, including mouse activity, to halt for a few seconds at a time. I have monitored my system temperatures and note that they idle as follows: NVidia 6800U GPU: 53degC System temperature: 34degC Athlon 64 6300+ temperature 45degC And at peak (throught freezing spells): NVidia 6800U GPU: 72degC System temperature: 35degC Athlon 64 6300+ temperature 57degC If I run Prime95, then I can get the CPU up to 62degC, but no higher. I believe the danger temperatures for the CPU to be 70degC+. However, I could not find anywhere what the max temp is for the GPU. though I note that the NVidia Tool offers a default threshold of 115degC. I have swapped out the videocard for a Radeon 9800 Pro, and whilst the performance is obviously slower, it doesn't freeze. I have aso experienced intermittent freezing whilst playing World Of Warcraft on full settings. I have swapped out both Crucial memory sticks with no difference. The motherboard is an ASUS K8N-E Deluxe. My next courses of action is to lend the video card to a friend for him to test on his machine. Anyway, you'd think this is a cut-and-dry case of videocard problems. Well, so did I. I sent the card back to Scan Computers International, whom I bought the card from, and who claimed to run the card through a half hour test on doom, far-cry, ,and 3dMark05 with no problems (and they charged me for the pleasure....). I also note that NVidia monitor shows the GPU Memory Bus speed permanently over the redline at 1100, whether idling or at load. I don't know what this reading is, but suspect it is misleading to the cause of this problem. Anyone have any ideas where else I could look???