I've got a Sparkle Geforce 8800GTS 320MB. She's more than two years old now but still chugging along nicely. I don't game at the cutting edge, but I would like to breathe a it of life into it to last until my next upgrade (whenever that may be.... )
Anyhow, I thought I would get some OC suggestions from the experts. A few specific questions:
1) My GPU runs quite hot. I've heard that this is a common thing with the 8800 series, but I'm not convinced. The card doesn't underclock or undervolt itself, but I've created a custom "Idle" profile using NVidia's Control Panel. Even so, it idles above 50C on the default fan speed, and goes to nearly 80C under load. Should I look at better cooling?
2) Any suggestions on a good overclock? The current values for core/shader/memory are 513/1188/1584. Do I bump them each by the same %, or is there a sweet spot ratio to aim for?
1) No, if you have the cash to spend on an aftermarket cooler save it for an upgrade.
Do not worry about those temps, GPUs are designed to take a lot of heat.
The G80 core is rated to run at up to 95°c with no issues.
If anything, use Rivatuner to jack up the fan speed.
My old GTS 640 has its fan running at 75% with about the same sound profile as stock.
2) Use Rivatuner to overclock and ATI tool to check for stability.
You should be able to get 600Mhz+ Core and 900Mhz+ RAM.
The Shader clocks are slaved to the Core speed but I believe you can unlock them.
Last time I tried (it was quite a while ago) I was unable to get it past what was stable from the Core overclock.
------------------------------If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669
1) No, if you have the cash to spend on an aftermarket cooler save it for an upgrade.
Do not worry about those temps, GPUs are designed to take a lot of heat.
The G80 core is rated to run at up to 95°c with no issues.
If anything, use Rivatuner to jack up the fan speed.
My old GTS 640 has its fan running at 75% with about the same sound profile as stock.
2) Use Rivatuner to overclock and ATI tool to check for stability.
You should be able to get 600Mhz+ Core and 900Mhz+ RAM.
The Shader clocks are slaved to the Core speed but I believe you can unlock them.
Last time I tried (it was quite a while ago) I was unable to get it past what was stable from the Core overclock.
Thanks for that. I'm glad to hear that my temps are OK. I have bumped up the idle fan speed to 70%, and I created a gaming profile that takes it to 90%.
Regarding the Shader + core clock, what's the connection? Is it a 1 for 1 increase in the shader as you bump up the core?
Not quite, the Core Clock and Shader Clocks are linked by a 1:2.4 ratio.
This means that every 1Mhz you add to the Core Clock will add 2.4Mhz to the Shader Clock.
It is sometimes possible to unlock this ratio and clock the shaders higher once you reach the limits of overclocking the core.
My experience has shown there is little/no extra headroom for the shaders past the cores limit but your card may be lucky.
------------------------------If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669
Not quite, the Core Clock and Shader Clocks are linked by a 1:2.4 ratio.
This means that every 1Mhz you add to the Core Clock will add 2.4Mhz to the Shader Clock.
It is sometimes possible to unlock this ratio and clock the shaders higher once you reach the limits of overclocking the core.
My experience has shown there is little/no extra headroom for the shaders past the cores limit but your card may be lucky.
OK, that makes sense. How about the memory? Is there an optimal value or should I just go for broke and push it as high as possible?
Yeah, go for broke.
Just make sure and keep an eye out for artifacts while you are testing your overclock.
------------------------------If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669
1) No, if you have the cash to spend on an aftermarket cooler save it for an upgrade.
Do not worry about those temps, GPUs are designed to take a lot of heat.
The G80 core is rated to run at up to 95°c with no issues.
If anything, use Rivatuner to jack up the fan speed.
My old GTS 640 has its fan running at 75% with about the same sound profile as stock.
2) Use Rivatuner to overclock and ATI tool to check for stability.
You should be able to get 600Mhz+ Core and 900Mhz+ RAM.
The Shader clocks are slaved to the Core speed but I believe you can unlock them.
Last time I tried (it was quite a while ago) I was unable to get it past what was stable from the Core overclock.
One more thing; I've played with RivaTuner before, but which ATI tool are you referring to for stability checking?
What you are really interested in is the 'Scan for Artifacts' button.
This will strain the heck out of your freshly overclocked GPU and usually alerts you when it outputs an error.
You may want to keep a manual eye out when overclocking your RAM, however.
I have noticed overclocking the RAM to far will not cause it to report an error but will show small white/yellow dots.
------------------------------If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669
------------------------------If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669