3870 is 3x faster in vertex/polygon performance than 8800ultra. So, if you’re worried about that, ati is the way to go since it has 320 stream processors vs nvidas 128. For some reason they actually work (up to) 3x better aside from being slower in mhz and only 2.5x physical more.
Why are games better on nvidia cards? I’d say its because game are not ready for unified processors yet and this is best seen with the arrival of 9600gt that has nearly 2x less shaders than 8800gt (64 vs 112). In some games 9600gt is actually faster than 8800gt(?!) simply due to faster clocks on it(650mhz vs 600mhz).
So, while games are nowhere near to accept 320 streaming things, 3ds max, on the other hand is.
There is something to note though. While 3x better performance seams nice and useful. See this link-
http://www.xbitlabs.com/articles/video/display/radeon-hd3870-hd3850_17.html#sect0
Note that for most purposes 2900xt(reviewed on the site) is just a bit slower than 3870 and that 8800gt is a bit slower than 8800gtx.
My other point is, 3x better performance seams nice, but the thing to note is that over a million polygons are used for that geometry +8lights test. And even though 200fps is 3x slower than ~600fps, even 200 is waay more than you really need.
So if you plan on gaming 8800gt 512 is the most cost effective card you can get.
And as for quadro insecurities, here’s a list
“under SPECViewperf in 3ds Max in openGL:
gforce 8800ultra gets 43.02
gforce 8800gt gets 43.18
quadro 5600fx gets 37.03
quadro 4600fx gets 37.07 “
If you can afford it 8800gts 512 is even better due to having full 128 shaders vs 112 of 8800gt.
Xeons are not usefull by themselves. They are basically the same core2 procesors you can get for fraction of the cost, but Xeons can interconnect so you could have an 8 core system or more.
Most cost effective solution today is core2 quad 6600 2.4ghz that can reach 3+ghz speeds easy.
Less than 4gb of ram is vasted. 8gb can be had for ~200$ and win xp x64 is the best work/game platform you can get today. Vista is still a toy, so for the moment stay clear of it, unless you want to game in dx 10.
What I have is a dual boot, one for vista 32 for dx 10 games, and win xp x64 for work/ other games. I spend 90% in x64