I have an ASUS GTX 470 (stock cooler), and a EVGA GTX 470 with a Zalman V3000f cooler. Both cards have been flashed with a custom BIOS to permit higher voltages than the standard 1087mV limit. Asus GTX 470: Runs furmark stable at Core: 770Mhz, Memory: 1700 Mhz @ 1070 mV. Furmark cannot push temps above 82 degrees. Folding overnight keeps temp at about 70 degrees. From this point on, any increase in clocks causes me to lose display within 3min of Furmark. I've tried pushing more voltage (upto 1200 mV). Temps are well within the threshold of 105 degrees (though I would not run it at anymore than 90-92 degrees) EVGA GTX 470 with Zalman Cooler Furmark stable at Core: 825, Memory 1800 Mhz @ 1100 mV. Furmark cannot push temps above 75 degrees. Folding overnight keeps temps at late 50s. Any further OC either causes me to lose display during furmark, or the card crashes during 3D Mark vantage, or return errors during folding (UNSTABLE_MACHINE). Tried pushing more voltage, but to no avail. Temps are well within control. With both cards, I'm hitting a wall I cannot explain. The cards are not limited by temperature, nor voltage. How can I push the clocks further? If there is nothing I can do, I don't get the point why people water cool GPUs when in all cases I'm not being limited by temps. Do I need to OC something else for stability? maybe northbridge, or something? I'm running a Phenom II x4 965 on a MSI 790FX-GD70, everything at stock. 2x2Gb GSkill Ripjaws 7-7-7-24 @ 1333Mhz.