Windows 7: Does overclocking decrease performance?

So according to 3D Mark Vantage, my gpu and/or cpu scores decrease if I set the Mhz to a certain range of numbers.



Is this suppose to happen or is 3D mark vantage is wrong?

Also which one to overclock more? the GPU clock or Memory clock?

Slight over clocking is suppose to improve performance. Pushed to far it may decrease performance and even cause problems, such as BSODs, I suggest forget overclocking.

ok but, is overclocking the GPU better or the memory?

I think that will depends on the purpose of the OC, but on average, I think gpu results are more consistent than memory OC.

How Do I know if I reach the limit of my video card?The temps r below 80 C in Furmark, I see no artifacts in games and benchmarks, and I pass the stability test in AMD overdrive and in Furmark.

I would start over , set it to stock and test it for performance , then adjust the speed of the gpu and ram some..and re-test.. Usually when you push a card or even a computer voltages need to be increased so dont expect a huge overclock on anything if your unable to adjust voltages