Why can I not display AA over x8 on my 4870?

[Freeman]

I recently purchased a 4870. Admittedly i havn't played many games on it yet but I have played Hellgate: London and done some FurMark stability tests.

I have Hellgate on full settings including DX10 however I can only set my AA on to 'Medium' (no higher options appear) whereas my brother with a similar setup and a 8800GTX can set his AA to 'Very High'

Also on Furmark when I do a stability test I can only set the AA to X8 whereas my brother can set his GTX to X32.

I am running on ATI's 8.6 drivers.

Any help?

Thanks.

 

[Freeman]

bump

 

[Freeman]

Are you using the hotfix drivers?

I'm not sure what you mean? I am using the drivers on ATI's website. Although they are named 3870 drivers I was told that they work fine with the 4870.