A 750w 80 certified PSU. It can handle it, I'm just wondering if my CPU would be a major bottleneck. I've read a lot recently and I just can't see if it would really be a major bottleneck at that resolution. Higher resolutions tend to be more GPU dependent from what I can gather.
That's definitely a tough one. The E8400 was a great cpu but using a dual core now is definitely holding you back in a lot of games and obviously it'll just get worse.
In saying that, as an MMO gamer myself I know that your particular games will be running fine on what you have. I'm also looking forward to SWTOR and GW2 but I think because they are aimed at the mainstream your current system will be more than good enough. Upgrading to a 560 or 6950 won't achieve much though, not with your cpu.
It's a tough one yeah. In your favour you should get some decent cash back for the cpu on ebay. I'd definitely go with a new cpu first, keep the 4870 and see how it works with your new 2500K and if it's not working out it's something else to aim for.
Yeah you tend to find that certain pc parts hold their value very well on ebay and the E-8xxx's are one of them. Obviously if you had a high-end mobo to go with it it's even better.
But yeah in your situation it's probably best to upgrade a part at a time. Also - your memory is probably worth more than DDR3 is now, I know that's crazy but DDR2 memory is more expensive than DDR3 in many cases. I noticed you said it was 1066, is it Corsair Dominator? If so that's gonna net you a good amount back as well, in fact chances are any 1066 DDR2 will get you some cash back which you can use to get cheaper DDR3 with.