Bit of an old topic here but I can confirm that running applications in the background actually improves the game's stuttering.
Pretty bizarre, but even on my ancient dual-core (opteron 165 oc @ 2.4ghz) having both my firewall (comodo) and browser (firefox) with its five homepage tabs open and minimized before running the game actually eases DKS's stuttering. In-game settings are generally on high, FPS cap at 60, looks great at 1680x1050.
