And the FPS is still horrible with your default AC? I would definitely start looking at the graphics driver installation. hope it helps,

Not sure if this relates to you, but within the catalyst suite what options have you enabled? Try AA: Enhance Appication setting, with Morph filtering offAF: Use application settingMake sure that Anti Aliasing mode is not set to super sample

Of course you are right, but nobody says the 5xxx are bad cards; or bad for fs. It's always ATI are bad for flight sim, and it's not true anymore, i am personally not convinced it ever was.

My coworkers has an identical system to mine, 'cept his GPU - 6970. He has serious fps when in cloud issues... now I'm not sure what drivers he's on but I don't have the cloud problems.

I have a 5770 too and have dismal frame rates, and have tried everything too... Literally everything. Yes that includes reinstalling, drivers, shader mod, fps limiter, defrag, ******* and other tweaks, overclocked to 4GHz.... Contemplating getting another GPU.

I too have a 5770 and am getting great framerates with clear skies. I'm using *******'s tweaks to an i7 930 @ 4.01 GHz, Nick's setup recommendations etc., shader 3.0 mod, and the latest CCC drivers (11.7). Throw some REX weather in there, and my framerates tank from about 30 down to as low as 9! I've had to turn AA mode to super sampling in order to kill the distant blurries beyond my LOD radius, which is set to default. I'm seeing others with a similar overclock and they're not complaining, and yet searching through these forums I keep seeing "I have a 5770 and clouds are destroying my FPS" posts. I'm beginning to consider upgrading my GPU, and would switch to nvidia based on the track record with FSX alone.