Winch nVidia GPU's are capable of 2 seperate clock cycle speeds for the core...
Standard Speed, which is used for desktop operations and general 3D use - essentially the most stable speed without doing any processor intensive tasks.
Performance Speed, which is more commonly known as 3D Acellerated Speed ... which is the ACTUAL speed of your GPU when it is running any GPU intensive application e.g. DirectX based.
My Creative Card is capable of 250mhz standard & 320mhz performance, both use different areas of the card's GPU for thier operations which is why they can be set to different speeds with no performance hit.
This is prior to the Overheating Symbol appearing (a little warning asterik after the mhz speed) ... this shows that the processors heat has exceeded the 95°f maximum safe heat range. If you attach a fan then your capable of pushing the processor a bit higher that this, can take it up another 50mhz without worry - but there is really no point going to far above the memory rating, and its best to try and keep the numbers synced at multiples of the other (else you'd get a jitter effect within Dx and OpenGL whilst one tried to catch up with the other)
all GeForce GPUs have a standard Core of 250mhz or above,
GeForce256/GeForce2/GeForce3 all have 250mhz standard Core speed
GeForce4 is dependant on a number of factors but most actually start at 300mhz and only the GeForceFX 5200mx has the core of 250mhz everything else is faster.
But the core speed directly translates to how many vertices you can push per second.
My advice to you Winch is to find out just how many Vertices/sec your card can actually push - and you'll know the real processor speed.
or you could goto www.nvmax.com and download Rivatuner
