8) The intel Pentium D 820 2.8Ghz processor is not you would call a gamer's CPU. I have the same CPU which runs good however overclocking wise is another issue. As you might have known, a lot of pc gamers/builders have issues overclocking the Pentium D 820 yet some gaming motherboard do not even register both cores. The 820 compare to that of 830 and 840 do not have the same features. The 820 don't have the 64 bit support nor the intel inhance speedstep technology. So that means that the 820 processor is I would say a fix processor, but Im not saying that you can't overclock it but like a say there are been some issues with the cpu when it comes to boosting the performance.
But a good high performance memory of 2 gigs and a decent graphics card ( 7800 gtx) would deffinitely increase your pc's performance. Some of the newer games that are coming out ei: BF2, FEAR etc. are taking more advantage of the vga/graphics card rather than just relying the CPU power. So an 820 processor with high performance memory and graphics card is good enough to run the latest pc games. 8)