Advice - upgrade or wait

I have been thinking about upgrading my system for sometime but with dollars being tight I am wondering whether or not I should go ahead with an upgrade or just wait and build build a new system sometime in the new year. Here are my current system specs and the upgrades I am considering.

GA-M57SLI - S4 ver 1.0
1 gig x 2 DDR2 800 - not sure of the make
Nvidia 8800gt 512
creative SB X-FI sond card
OCZ 600 watt Game X Stream PS
AMD 64 X2 4200

Upgrade the video card to either a nvida 280gtx 1meg or HD4870x2 with the intent of keeping it for a new system build sometime in the future. Upgrade the CPU to AMD Athlon 64 X2 6400+ dual core.

Thanks

You have a pretty well balanced system there.
If you upgrade the vga card, you will also need to upgrade the cpu to drive it properly.
Once you have to upgrade multiple components in concert, it is time to do a whole new build.

VGA cards are constantly getting better, with more performance for your dollar. I would not invest now on a card for the future. At least wait to see what the Nvidia 55nm parts look like.

If there is one upgrade that would probably be worth it today, is to go to 4gb.

If you got the 4870x2 you might have to upgrade PS. Also, either of those gpu
s would be limited by the cpu so you wouldn't be getting the full benefit from them. I'd say if anything cpu, otherwise save up and go all out in when the next generation of cpu's and gpu's are out.

The CPU is probably one of the cheapest upgrades for you, and a 3-core Proc for $100 is a steal. Personally I'd wait on the next gen Quads at the beginning of next year(Vista 64 has issues with AMD Quads). Then that leaves you to save a bit for a better Vid later (recommend the 4850, or 4870). Also recommend more RAM (2x2GB DDR2 800 is around $70).

http://www.newegg.com/Product/Prod [...] 6819103254
$100 (AMD 8450 Tri-Core)

Which OS are you using XP, or Vista? both will see a slight performance gain from more RAM (Vista will see the most benifit). The new CPU with either higher speed, or 3-core will help too (depending on weather the MB can support Phenom)

P.S. Your MB cannot support Phenom (as it's only an AM2 board)
I'd recommend this one however: http://www.newegg.com/Product/Prod [...] 6819103289
$77 (AM2 5400+ BE, unlocked multi)(I can get my old 5000+ BE to 3.1)

Like what most other posters mentioned, CPU is the best upgrade for you. I just checked your CPU support list and you can even get http://www.newegg.com/Product/Prod [...] 6819103273 .

Your motherboard does support this CPU, but you might need to update your BIOS. I would double check with Gigabyte's tech support to make sure.

the 6000+ would also work, but as I mentioned that 5400+ is a black edition (and can be OC'ed higher than the 6000) it is also $15 cheaper (OEM, no HSF) so for a cheap HSF I'd say this one: http://www.newegg.com/Product/Prod [...] 6835185125
Arctic Cooling Freezer 64 Pro $30 (you can get a very good OC out of this too)

Like all the others, I say wait. I have a similarly aged intel setup (e4400 p965 chipset), but have the same problem - you will not get a performance boost that is significant for the money spent. Once you upgrade one part, you need more to take advantage of it. It's the cycle of cash, to quote the Lion King.

I'm glad logic prevailed in my head, I have a tendency to want to upgrade a lot, and I have finally realized that it is much better spent money if I wait to upgrade the whole platform at once.

Differences will probably be negligible if any. At stock I believe both CPU's run equally well. Differences might be how well either CPU overclocks (in the case of 3.0 ghz Athlons they don't overclock that well anyways).