AFAIK all these screenies are of 1900xt/xtx in CF. The kind of min requirements you ppl are speculating are more than those of professionals who are speculating for something with decent detail and not exactly minimum. Here is what the system requirements maybe like:
Minimum:
Intel 2.4-2.8GHz hopefully without HT required
512MB-1GB RAM(1GB for Vista)
128MB SM 2.0 card, geforce 6600/6200 or higher
640x480 lowest-low
Minimum Recommended:
A64 @ 2-2.2GHz for 90nm CPUs, another 200MHz for 130nm CPUs, Intel 3.4-3.8GHz
1-1.5GB RAM
256MB Geforce 6800GT/7600GT
1024x768 med to low OR 800x600 med
Recommended:
Dual core recommended or atleast AMD 64 3800 or Intel 4.2GHz
2GB RAM
256MB-512MB Geforce Radeon X1800XT/Radeon 7900GT
1024x768 high to med
Near Full Experience:
Dual Core or AMD 64 3800 or Intel 4.2GHz, dual core strongly recommended
2GB or more RAM
1024x768 med to high or high or near MAX
Radeon X1900XT/Geforce 7900GTX
Full experience:
As above
2-3GB or more of RAM
Geforce 8600GT or better
In case you have single cores, reducing things like physics, sound etc a little may improve performance and make it playable.