I have had this from day one. I built this PC just to run this game and started out with using some new and old parts just to get up and running. At first I figured it was stuff like to little ram, under powered video card or that I was using a parallel ata hard drive. I kept upgrading hardware and honestly I have seen a minimal performance increase. I of course played around with the settings and tried settings I have seen recommended on random topics over the months. Tho I rarely see anyone else with a setup similar to mine. I have some settings that seem to be the least troublesome set atm. Every time I upgraded something I would think "this should fix it" I were wrong.
Windows 7 Ultimate 64-bit Service Pack 1
Motherboard: ASUS M4A89TD Pro/USB 3
Processor: AMD Phenom II 1090T X6 CPUs 3.2GHz
Memory: 12288MB RAM @ 1600 Mhz 7-8-7-24
Video Card: Radeon HD 6850 1GB 256-bit GDDR5 (pre-overclocked)
DirectX Version: 11
Hard Disk: 2 Western Digital Caviar Black 1TB 7200 RPM 64MB Cache SATA-3 6.0Gb/s in RAID 0, so basically a 2 TB 14,400 rpm 128MB Cache 12Gb/s HDD
A $80 Zalman CPU cooler & each HDD has its own 120mm cooling fan
PC case itself has 4 high CFM 120mm fans 2 push 2 pull
And a 1000 Watt PSU to run it all
Game settings Full Screen (runs better then in windowed)
Window size: 1600 x 900
Multisample: 2x
General drawing quality: 8
Background drawing quality: 3
Shadow detail: standard
Ambient Occ: off
Depth of field: on
Texture quality: high
Texture filtering: standard