Always had issues with slowdown on my rig, even with very conservative settings (Medium Textures, Low Quality on most other settings; using Environment Mod with Draw Distance of 1 and Detail Distance and Traffic Density of 35 with modified popcycle; only using modified default vehicle models.) I think I read somewhere that my GFX card lacks power, and I would hope my CPU and RAM would be sufficient, any ideas?

Processor: Intel® Core i7 CPU X 980 @ 3.33GHz (12 CPUs), ~3.3GHz

Memory: 9216MB RAM

Card name: ATI Radeon HD 5570

Display Memory: 2282 MB

Overall, your specs aren't the worst. You should try overclocking your GPU. You have a good Processor, and if you get a better Card, you should be able to run the game on higher settings.

I just checked, and 650 MHz Core and 800 MHz Memory speed seems a bit low. I'll take a look into the clocking for now, thanks for the tip, but getting a better card looks to be requiring a better power supply... this for sure was the last time I buy a pre-built instead of upgrading...