System is

2 GB DDR2 800
Geforce 8800GTS

But which CPU should I get? (no over clocking)

Total system price differs less then $10 so that makes no difference either but makes it harder to chose...

At stock speeds the X2 5200+ would be slightly faster so I'd go for that. The E6400 would own the X2 if you're overclocking, though.

I would go for the E6400 because although the performance is similar its looking like it will be better to stick with intel for this coming year if you plan to upgrade at all.

Haha, well if you've got the benchmarks for the Stars processors...show them to me.

This guy's a fanboy, things could go either way this upcoming year. If you're only options are those two, go with the 5200+.

edit - if you want to overclock, go for the 6400. You'll be able to get a lot more performance out of it, then, more than the 5200+, even overclocked (probably).

Yes, when overclocking, AMD doesn't stand a chance.
This because to have similar performance, the X2 needs to be clocked significantly higher (2.6GHz VS 2.13GHz), and the maximum overclock potential of AMD is 3.0-3.2GHz, while C2D could reach 3.5GHz or maybe even more (and it would take an AMD 4.0+GHz to match that in performance).
But if you don't want to overclock and the price is the same, the 5200+ is a good choice.

6400...Same performance, and $100 cheaper. If u decide to OC later (which u most likely will), the 6400 has much more potential.

6400 For The win! I have mine at 3.4ghz on air with just 1.325vcore rock solid P95 stable for 14+hrs.

He said that he could get them for the same price.

I'd say get the E6400.

The Core 2 line is totally new and is going to have quite a lengthy lifespan ahead of it (well, in IT terms anyway)

The AMD line is wheezing along now compared to the Core 2, much like the old Pentium 4/D line has been wheezing along previously. AMD will be desperate to bring out new technology to help them compete on performance again, this means their existing processor line is likely to have a relatively short future.

I suspect Intel is holding back on releasing higher clock speeds until it needs to, waiting for AMD to make a play and then respond to it quickly.

Anyway, Core 2 is new technology and it's going to be around for a while, meaning you'll be future-proofing your PC much better. Get the right motherboard and you'll be able to upgrade to quad core later on (or maybe even beyond that, 8 cores?)

for a performance pc.
nothing but core2
if oc later, defect most of amd line.

for other range(lower price), sempron & amd x2.
but they won't go with the Gefore8 anyway.....

E6400 FTW
It will annihilate any X2

The 2 cpus are pretty much the same in overall performance, but personally i would get the E6400 (lower power consumption).

There are some factors being overlooked...
The AMD CPU has onboard memory controller - so AM2 CPUs may cost more but the mobos are usually less expensive.
Also, Core2 CPU could save some money on memory as DDR2-667 is perfect.
AM2 works best with DDR2-800 (and you will need better if OCing).
So: the three should be priced up together, ie. CPU/mobo/RAM. This is why he says overall cost is comparable.
But as for just CPU, lemme see here...
The x2 5200+ is $465 CDN; even an x2 4600+ is $300 bucks!
The E6400 is only $260 CDN (and memory costs less too).
You would have to get a free mobo to make AM2 worthwhile...
However, I build a lot of AM2 systems using A64 3800+ (single-core) @2.4GHz which is a good deal and still very fast.
But x2 5200+!? No thanks LoL - I can get a mighty E6600 for $365 bucks ($100 less).
Regards

y'all are so drunk on this OC crap, 2.5GHz is enough for anyone except the most "extreme over the top moneys no limit gotta have the fastest chip in the world i got bragging rights gamer"...
3GHz for servers and workstaions running multiple apps...
Back before we had access to dual-core chips and megaspeed cpu's overclocking was necessary to achieve the required performance levels for a specific program to run correctly....
Now it's just a game of who has the fastest processor, never mind the fact that it's overkill and mere mortals cannot harness the full potential of said speed-demon......but it's still cool.
Focus your energy on something constructive, like using all that power to create world peace....
I'm not singling you out bro, just hitching a ride on your thread

Dog! Great post, I agree completely. I was gonna say myself... (but not as eloquently).
The nice A64 at 2.4GHz is fantastic for most people.
I could buy three of them for those prices! Heheh...