OK. I recently got a Zotac GT240 1gb GDDR5 and it's awesome for the price I paid! Now having a 585W PSU I overclocked it to the following(without volt mods): 660(Core)/1608(Shaders)/2000(Memory). The stock clocks are: 550(Core)/1340(Shaders)/1700(Memory). Is it OK? I can probably take it further too but I'm probably going to have to get some more fans for my case. And is it even worth overclocking it?
I have this slight problem with drivers and FPS. Every now and then the drivers stop responding and recover. When that happens the screen goes black and when it comes back my FPS will have dropped by probably around 60%! I'm using the 260.99 drivers. An example of FPS before driver crash:
Far Cry 2(DX9, custom some high and some low like Post processing and geometry)= 80-120FPS after crash= 22-31FPS
S.T.A.L.K.E.R(Enhanced Full Dynamic Lighting DX9, everything high)= 44-60FPS after crash= 6-18FPS
Battlefield 2 does exactly the same thing. Company of Heros I have not noticed any real difference although performance is REALLY low compared to benchmarks. All the games are on 1024x768, 2x AA in nVidia Control Panel(can't go lower) and 0x AF. This bother me extremely to think that I can go higher(settings) but because the drivers aren't working I can't do that, as they usually crash within 10 minutes.
Temps are very low. Last time I checked CPU during Far Cry 2 it was 48'C(i5-760), system temperature 31'C and the maximum GPU temperature was 51'C. Could heat be the problem? And do note: My system was running the ENTIRE day. Temperature was probably around 28'C outside. I was playing Company of Heroes, Far Cry 2, Splinter Cell Double Agent and Battlefield 2.
I had the exact same issue with my GTX 260s (SLI) when using the 260.xx drivers and sorted the issue by using the 197.13 drivers which I find to be the best drivers for my system.
What is happening is your card's drivers are failing and then recovering, but when they recover they're staying at it's 2D clock speed which is often around half the 3D performance (full) speed. This is why your FPS are destroyed when this happens.
Google around to get some of the 197.xx drivers and install them instead of the latest. I'd put money on it that it'd solve your issue!
FYI, I had and solved this issue only this morning after needing new drivers following a bios update.
Well you say you can push it further, but it sounds like it's unstable. Remember not all cards are the same as some GPU's can be overclocked to the moon and back, and others can't stand a single MHz increase - just how it is.
Try doing stability testing with Furmark and similar programs.
Well just have a play around then. Get a few different drivers and test them all, some will give better performance and others better stability with overclocking etc. And yeah.. maybe another 2GB would be nice hehe.
This is an old thread, but for anyone who had similar problems to the OP, I found out that in RivaTuner there is an option to force performance mode and this stops your cards downclocking while in 3D gaming mode. I found this out earlier because after overclocking my cards I was crashing and underclocking in game.. now I'm stable and it doesn't seem to underclock any more.
You can find the option under "power user" > rivatuner \ nvidia \ overclocking > right click on "enableperflevelforcing" and select the lightbulb.