I have a Sparkle 9600GT and got no issues at all. The drivers I use are 191.07 and on Windows XP.
I also haven't felt any need to "upgrade" yet... But then again I don't play much newer games...
You can use NVIDIA's official package for overclocking: http://www.nvidia.com/object/nvidia_system_tools_6.05.html
It will then show up in your nvidia control panel under performance.
My factory shipped frequencies are:
Core clock : 700 MHz
Memory clock : 1000 MHz
Shader clock : 1850 MHz
So you could try that to see if it works better.
I think it also has a cooling/fan setting.
I also haven't felt any need to "upgrade" yet... But then again I don't play much newer games...
You can use NVIDIA's official package for overclocking: http://www.nvidia.com/object/nvidia_system_tools_6.05.html
It will then show up in your nvidia control panel under performance.
My factory shipped frequencies are:
Core clock : 700 MHz
Memory clock : 1000 MHz
Shader clock : 1850 MHz
So you could try that to see if it works better.
I think it also has a cooling/fan setting.