I have the choice of buying an Opteron 170 or X2 3800+. If I buy the X2, then I can afford a graphics card upgrade to 7800GT. With the Opteron, I'll be stuck with 6800GS. Which one should I choose? I need to build this computer for professional work such as Photoshop and Illustrator, as well as for gaming.

I have the AMD X2 3800+ and I am a avid user of photoshop and illustrator. It runs very well
The 7800 GT is a great card and can play most games at their highest settings.

I am not sure of the performance advantage from the Operton and the X2.

Make sure you buy some decent memory

Hope that helps

supposedly Opterons are more reliable

hmm. it is a tuff choice. but go by this, is the 170 available anywhere? what is ur budget for these 2 items?
i have both the opteron 170 and evga 7800gt and they are just great together, 7832 in 3dmark05

I have a budget of $1400.00 for the overall computer, including tax ($1285 without). Already have 2GB of RAM ($210) and plan to get 2 Raptors ($280). The rest of the money goes to the case, fans and heatsinks, motherboard, DVD drive, USB drive, headphones, processor, and video card.

tax, where are you getting this from? newegg is where you should get it, they have no tax

give me a whole layout of what you plan on getting

Another choice: Opteron 170 or X2 4200+ if I do decide to go with the 6800GS. X2 4200+ has a higher clock, but only 2x512KB L2 cache.

i would go with the x2 4200 cause it has a extra 200mhz on the opteron

For me I'd go with the opteron... why?... bigger L2 cache, Bigger clockspeed means nothing nowadays

Unless you play games, then everything means clock speed. Cache is most useful for rendering and compression. If you use Adobe products or are into video encoding/decoding, then the opteron is better.

The buzz with the dual-core opterons is they overclock very well, and use low voltage. From my experience with both, they run almost identically, with the opterons better at rendering tasks (b/c of the cache).

If you're building to game, the X2 is better (same performace at a cheaper price point). Some say the Manchester cores (512K cache X 2) do not OC as well as Toledos (1MB cache X2), but that is luck of the draw. Depends on the chip only. I've seen 3800+ X2 clocked at 2.8GHz on air. Mine runs at 2.4GHz on air with memory at 2-3-2-6 (1:1) at 240FSB and benchmarks at 4800+ Toledo levels in Sandra. I took it up to 2.7GHz but was uncomfortable with the heat (55C at load) and did not want to spend more $$ on cooling.

But ultimately, if you're building for gaming, the extra cache does not help (at least today - as games evolve, this may make a difference in a couple years).