So I've been thinking of upgrading my graphics card (Age of Conan in sight...
But I think I'd need to upgrade more than that.
So there's the AMD Athlon 64 X2 3800+ (Socket 939) problem. When I bought it, I wasn't aware that Socket 939 will be obsolete soon. Now I want to get rid of it and buy something better.
Then there's the DDR Ram which I'm returning for repairs now, I should get new modules I can sell (and for a good price too, I reckon).
As you can see, I'll need a new motherboard as well.
This is how it looks then :

1. Replace AMD Athlon 64 X2 3800+ (Socket 939) with Intel Core2 Duo E6550 2,33GHz (Socket 775).
2. Replace Corsair TwinX DDR 2x 1GB 400MHz C2 with PDP Patriot Dual LLK 2x 2GB DDR2 EPP 800MHz CL4.
3. Replace Asus A8N-E nForce4 Ultra with Asus P5K Intel P35.

About the graphics card...now I have Radeon X1900XT Sapphire 512MB VIVO / 2xDVI and I've been thinking of buying Radeon HD 3870 X2. Well, it looks nice and the price's good.

What you think?

sounds good and can't see any problems. 3870 X2 should perform to meet your needs and motherboard looks good also. Only thing I would say is try going with a 45nm CPU (probably E8400 in your case). The P35 supports them well, they run cooler and better overclockability. Not a huge price difference either. just a thought.....

What do you think about those RAM modules? I've heard some good things about Patriot modules, but I'm open to suggestions
As for the E8400, I might look into it, but is it truly worth the higher price?

One more thing : I've got Hiper HPU-4B580-MU 580W PSU - will it suffice?
And what about Scythe Infinity cooler? It should fit with the Intel socket 775, am I correct?

If you think the higher price isn't worth it, look at the E8200 - its still a very capable CPU @ 2.66 ghz its the equivalent of my E6700 and you should be able to find it for about $225 (not sure I live in the UK)

I've heard good things about Patriot RAM recently. I can recommend my 4gb of Corsair XMS2 C5 which are excellent. RAM is one of the hardest things to choose due to how many different brands there are. In your situation I would just look for good timings from a well known manufacturer.

As for the power supply. I think (although I'm not sure and you should have a look on the ATI website) that the minumum power requirements for the 3870 X2 is 550w which considering the rest of your system is quite powerful may be pushing it a bit. I've also heard that 1 x 6 pin PCIe is required for standard use but if you want to use ATI Overdrive (not really sure if this is worth it as I'm not an ATI guy) for enhanced performance you need 1 x 6 pin PCIe and 1 x 8 pin PCIe (again, double check this on the ATI website). So you may want to check your PSU has the correct connnectors as well.

Hope this helps a bit. Any more questions just ask.

What about OCZ Ram? OCZ Technology 4x 2GB DDR2 667MHz Titanium AM2 Quad CL5 looks like an overkill to me, though
I've got Corsair RAM now and it's malfunctioning (I'm returning it) so I'm not so trusting anymore ;P Yes, I know RAM modules are especially prone to this, but still...

As for the Power supply - I'll most definately buy a new one with the new graphics card - in a few months. For now, I'll just buy RAM, Mobo and Processor.
And by the way : How much are worth 2 year old AMD Athlon 64 X2 3800+ (Socket 939) and Asus A8N-E nForce4 Ultra?

Thanks for all your help.

not much....

I was counting on about 100 $ for both. Is that feasible?

i would think so... maybe a bit more with the case?