I can run with literally everything maxxed out and don't ever notice it dropping off of the refresh rate. I ended up turning the self shadowing off however, it just ended up being too distracting to me. I found I was watching shadows play through my cockpit and not watching the bad guys too frequently. When I run shadows I run them at the 4k level and haven't noticed any framerate difference at all from having them on or off. I've got a Phenom2 quad core 3.2 with 4 gigs of ram and the MSI factory overclocked 5850, nothing in the game has handed it a problem yet. I figure I've got about 2 more years before it's upgrade time again.
I played around with my ATI card setting last night and found that I can run Object datail maxed, Ground detail set to 3 miles, with everything turned on including self shadows at 4096 (smooth shadow set to off) and get a pretty steady 59f/s in furball over an airfield. I followed the tips on the AH boards for Catalyst ATI settings, namely...
Turned off application settings,
set AA at 2x with a box filter (x2),
Turned Open GL tripple buffering off.
Also important to note, I followed Skuzzy tips about shutting down the various usless (to running AH) processes. That may have also been a factor as I did that first and played with the card second.
Looks great. Loved the way the canopy frames move around the IP and over the wing when maveuvering in the sun. The strange part is that the smooth shadow option for the self shadows tends to blur and smear the shadows so much that the detail from each image being shadowed is almost completely lost. The shadows seemed clearer and more defined with smoothing turn off. I assume the smoothing was supposed to take the saw tooth out of the edge effects but it doesn't wok nearly as well as AA does on the object polys. The shadows look much better with it off and with a increased resolution, which was less of a frame hit than smoothing was.
I'll play around siome more today and see if I can eek more out.