Hi, I'm new and unfortunately not very tech savy. I have a HP Athlon 2.5GHz dual core, motherboard M2N68-LA with intergrated GeForce 6150SE nForce 430 card with 250W power supply. Not a big gamer but enjoy half life etc. Just wondering what is best bang for buck on small budget and what is compatable for this machine etc etc.
a 250w will not power the 4670, try the 4550 for the cheapest fix or upgrade the PSU for future games. Luckily Valve does a good job optimizing their PC games and the 4550 will have no issue running Half Life 1 or 2.
A 9500GT doesn't use up much power. Since you got a half step multiplier (12.5x) I'd assume that you have the Brisbane Athlon X2 so that doesn't use up too much power either. A 9500GT would be just fine in your system. The Radeon 4670 is much better, but uses considerably more power and would really be pushing that cheap PSU. If you have money to upgrade your PSU and get a decent video card then go for it. If not then just get a 9500GT for now.