Radeon HD 4550 overclock problem

Hi,

I have a Gigabyte Radeon HD 4550 128mb hypermemory and a Dell inspiron 530s PC.

Ive currently overclocked my Graphics card to a core speed of 730MHz and a Memory clock of 950MHz using ATI tray tools, but when i go higher than that the card shutsdown in less than a second!, i thought of this as a temperature issue but the card runs at 70 degrees at full load. From my own knowledge i suspect this is because im trying to clock my card faster than my PCI-E bus and cant outrun my RAM which is, 2GB DDR2 SDRAM 667MHz.
If i can get around this problem will i be able to clock my card even higher??

Hi and welcome to Tom's forum.

What voltage are you using for the GPU? Because I think that's more a voltage problem that other thing.

Exactly, too low voltage for the clock that you are trying to use.

What PSU do you have?

So, you have a OEM build right?

Then I see a problem here, that PSUs aren't for overclock and we don't know the quality of the voltage and power than they gives you.

Regarding your question, if you keep the voltage in the safe limits and the temps are good too, you can rise as much as you can.

Not really, you need keep your eyes in the temps HWMonitor or the same MSI Afterburner.

Not your board, that just kill GPU BUT if you don't do it in the proper way.

That rise quickly and you will see screen artifacts.

Thanks for your help, iv managed to reach a stable clock of 750MHz & a memory clock of 1000MHz at 1.2v & 74 Degrees max

Is there anyway to tamper with the Shader clock, or any other settings to improve performance?? such as bandwith, or the number of stream processing units??

I think the only parts i can overclock are the Core/Mem/shader clocks, but iv read that the shader clock can improve performance alot, especially for games like Crysis and Halo

Im not sure that ATI cards have shader clocks