Overclocking Mobility 4570

[Justin Haynes]

Hello, I have this video card and I'm looking to overclock the memory (vram) of it.

I managed to overclock the core from (stock) 680Mhz to 850Mhz. (using rivatuner) but if I barely move the slider for memory OC a tiny bit (example from stock 800mhz to 801mhz) my entire system crashes.

Any idea what's wrong and what I can do to fix it? Thanks.

 

[Justin Haynes]

Oh and my system specs just in case:
Intel Centrino Dual Core 2.0GHz
2.5GB ram (was 4, 1 stick died)
Mobility Radeon HD4570 512MB GDDR3