Asus EAH5850 wont overclock

[Hotchip]

Hi guys

I bought a 5850 EAH5850 recently to replace my old 9800gt. Im trying to overclock it at the moment and failing to get even the slightest overclock. Tryed smartdoc and MSI afterburner but just makes the screen flicker even if i just bump the coreclock up 5 mhz. Ive read that people are getting some serious results with this card anyone know what im doing wrong?
Am i surposed to to be putting up the core clock and the memory clock to a specific ratio?

Spec :
Q6600 @3.3Ghz 1.43v
corsair H50
4GB 800Mhz ram
AsusP5Q pro turbo
Asus EAH5850
Galaxy 850w PSU
Windows 7 premium 64 bit

 

[cobhc]

I'm assuming you're bumping voltage up as well? I can't get mine to overclock much either, but I can hit 950 on the core or so with max voltage.

 

[G-Dubs]

using only smart doc I can get mine up to

1000 engine
mem 1225 (4900)
voltage 1.3
fan 48% (keeps it cool and is bearable, but you can put it into smart mode but the constant ramping up and down can get a bit tiresome

The above returns a 3d mark of P20858 using vantage.