Gaming monster + media server + Internet + Photoshop = No real need for more than 4 cores. Also no need for Hyperthreading.
-Best AMD CPUs, then, are the Phenom II x4 965/970 (3.4/3.5GHz, for Locked/Unlocked, about $200US). Intel has either the i5-760 (2.8-3.4GHz, about $205US) for Micro-ATX systems or systems which will only have one graphics card, or the i7-870 (2.9-3.6GHz, about $300US) with Hyperthreading turned off in BIOS for full-size systems or ones which will use multiple GPUs in SLI/X-Fire. The only way to get more performance than this would be something in an LGA1366 (i7-9xx), but then we're talking $500 or so for
just the cpu.
-Board should be something based on 890FX (for AM3), or P55 (for LGA1156). If you went crazy with an LGA1366 CPU, then you're stuck with X58 as pretty much your only choice (at around $200-300 for the MLB) but at least you get lots of PCIe slots.
-OS should be Win7 x64. At this time, I don't believe there is any other reasonable choice.
-8GB RAM as 2x4GB modules should be ideal.
-Right now I tend to recommend Seasonic PSUs, they have the X-850 which is
incredibly efficient at low power draw and which has an extremely silent fan design (to the point of actually turning the fan off when it is not needed). 850W should be plenty, even for dual 6870s (even
a high-end X58-based system can get by with under 400W* if it is using only a single 6870)
-Either ATI 6870 or GeForce GTX 460, making sure they have at least 1GB memory onboard. Remember that almost any board with multiple PCIe x16 slots can do Crossfire, but only certain ones (ones NOT made by ATI) will do SLI for multiple NVIDIA cards. If you get the AMD motherboard, you will be limiting yourself to only a single GPU if you want to use NVIDIA graphics cards (and if you use Photoshop a lot,
you might).
-For sound, get whatever turns you on. Unless you're doing some sort of audio editing, built-in sound these days is usually good enough (5.1/7.1 surround) for most people.
--Patrick
*Test done with that system at full load
shows 247W draw at the wall outlet
for the entire system. Assuming 80% efficiency for the 1000W PSU tested (which should actually be a little low), that means the components in the system are using about 310W worth of PSU capacity (247W / 0.8 = approx 310W).