Seems a pretty obvious question but I'm not sure were about i should draw the line in terms of overclocking the graphics card.
I bought the ASUS eah5850 DirectCU gpu for my build, i begun with overclocking the graphics card first rather than the cpu, because im wanting a rather large oc for the gpu, but i only want a 3.6GHz on the cpu(which is i5 750).
Okay so, i've been using Afterburner in conjunction with smartdoctor(which i have not used yet), i also have catalyst control downloaded though i dont like it so aint using it. I have 3D mark vantage which i found a key for the advanced version, i also have SiSoft sandra and Furmark.
So basically i have been slowly increasing the Core clock from the factory 725MHz...i am currently at 920Mhz, and the memory from 4000MHz to currently 4880MHz.
I have ran the SiSoft graphics tests and a 3DMark vantage after ever increase, and have recently begun using the Furmark after my recent increases. The temps are stable at 42 Celsius with the fan at 50%, after running furmark for 30mins the very max temp i have seen is 75 Celsius.
Furmark seems to run without any visible problems. Also i have not changed any of the voltages yet.
Am i failing to notice something? and what should be the outcome when i do meet the limit, how do i know?
One final question, if i may, i have read that over 1000MHz and 5000MHz that performance begins to reduce quite significantly, whats your take on it?
Thanks for your time,
P.S are there any software utilities that give you power consumption readings?
I have two GTX 260 (216)s in SLI. When overclocking them I used to get a good increase in performance, but now with the latest drivers I actually get a decrease in performance when overclocking over 700MHz (from 576MHz stock). I get best all-round results when leaving them at stock settings now instead of running them with a hefty overclock. Not sure why? But almost certain it was a driver update.
You'll know when you've hit the limit because you'll get artifacts or random display-driver related errors.
Running crysis benchmark, gta4 benchmark etc is a good way to get artifacts to show themselves if you think you're hitting the roof. When testing mine for limits, crysis had artifacts when furmark and vantage did not.
I will try testing out my OC on a game later, downloading napoleon totalwar at the moment.
I've now got myself upto 920MHz core clock and 1285MHz memory clock, still without a voltage change with fan at 50%, getting a max of 72 Celsius in Furmark. with H12338 in 3dmark vantage at high setting.
Still not noticing any artifacts.
You are going to have to give the card some voltz if you want results, leaving the voltage at stock while pushing the card past 920Mhz is just going to lock up your system. I run my DirectCu at 950/1175 1.2v or 1000/1250 1.25v depending on what I am doing.
Here are some examples :
After an hour of playing BC2 :
So to answer your question you will see 2 things happen when you have pushed the card too far, it will either lock up your system or you will get artifacts.
Dont hesitate to raise the voltage on your card, as long as you monitor your temps and DO NOT GO OVER 1.3v you will be fine.