Q: When overclocking my ATI X1800/X1900 graphics card, what is my safest max voltage for [insert your cooling here] ?
A: For the following cooling options:
-Stock cooling: If you are going to be overclocking you ATI card with stock cooling then you should try to keep the fan speed pretty high, I mean 80-100% fan speed obviously this is going to be what do you expect, but it’s not just the core temperature you should be worried about, the voltage regulators get extremely hot, I would strongly recommend you get a fan blowing on them, it lowers the temps substantially, I got my mine down by about 20C (60/100c to 40/80c (idle/load)) with a single 80mm fan.
With the stock fan speed up and a fan on your voltage regulator you should be ok for the max core voltage (1.575v) but if aren’t using an additional fan or running on slower fan speeds then I’d recommend that you don’t cross 1.45v otherwise you’ll have some issues with voltage regulator temps.
- After market air-cooling: With an aftermarket air-cooling solutions you should be ok for the max voltage as long as your core and voltage regulator temps are down, if your cooler doesn’t cool the voltage regulators then I’d once again recommend you get a fan on them just to be on the safe side.
-Water/ LN2 / DICE or phase cooling: Well what do you think , as long as the voltage regulators are cooled substantially you’ll be fine for max voltage, hell you could even get ambitious and get some 1.6V+ volt mods in there...
got this from
http://forums.bit-tech.net/showthread.php?t=116404