Xpx64 vs Vista64 preview speed

quoka wrote on 1/25/2009, 7:21 PM
Couldn't work out which previous post to slip this one into so started a new one. Have upgraded computer and OS from -
XPx64/dual-dualcore opterons TO Vista64/Dual Xeon Quadcores.
Have both systems running 8.0c & 8.1.
My preview under XP is much smoother but the render times under Vista 64bit is faster.
I expected the faster cpu intensive renders from Vista but feel like I stepped backwards with previews. Previews that would reliably play back full frame rate in XPx64 now drop down to half the speed (at times)in Vista. (using Identical settings). We run off a Raid server over ethernet - can copy files at identical speeds on both systems, but Vegas seems to not like the new OS/hardware combination.
Anyone else seeing the same , or anyone with any suggestions?