i had a buddy who had a 1.2 Athlon, 384MB of PC100 SDRAM, and a GeForce 2 MX200 and he could run HL2...Believe it or not.
Ahh, yea i beleive you. but thats when you put in the 'Directx Level 7' command. and run it on low. so it looks like **** with prolly 30fps and lower. so for single player mode, its practially uselss because theres no special effect that HL2 is famouse for.
i tested HL2 ona 9100 IGP ati, hardware DX 8.1, and by using the DX 7 command i could doubled the fps.
Note) on DX 9 hardware like, 6600gt. using the DX lowerlevel command didnt benefit at all, with very low fps increase.. while still a huge decears in quality.