Hi,

Interesting, very similar setup to my server.  I used the EVGA GeForce 88000GTX and an
ASUS P5W DH mobo and slower SATA drives (2x 500 mirrored boot, 2x1 TB striped)
 
But same processor and same RAM.

Your link is for the CAL's for it, you dont' care about those.

Windows 2008 x64 Server.  Actually the interesting part, the basic install of W2K8 Server is
"less" crap than you get with Vista.  You have to go "enable" stuff to install it.  So for example
media player and aero etc, are check boxes that you install afterwards using (Programs And Software...in Vista/W2K8).

Windows 2008 is the "server" version of Vista.  This means it is the more stable/scaleable
version.  Traditionally this didn't do much for speed. However, in this case I have found
W2K8 to be a lot faster.  It came out a good year after Vista so they had time to get
things "right"

From a day to day point, if you don't install the Aero stuff, it looks like a cross between
XP and Vista.  if you install the Aero stuff, you won't be able to tell you are not on Vista
other than speed and a few Aero features like the Preview.

However, if you've already bought Vista x64...not sure that it is worth it.

Basic cost for Standard is like 2x Vista Ultimate.  There are other reasons/features that
cause this cost to be justified, but if you aren't going to use those features....it's an expensive
boost.  (although some of them you could find useful...like legally having 3 people being able to  use it at once, independently, via console/monitor and 2x remote desktop sessions and
some of it's very useful point in time file restoration features; and the ability to legally run a second copy of W2K8 standard inside as a virtual server; and if you have other computers in your house that have XP pro or Vista Business/Enterprise/Ultimate, you can create a domain and then life is so much nicer...but that's another story for another day)

--actually running the second copy of W2k8 as a virtual server might be interesting as
a work around for QM's problems.  if QM refuses to use more than 1 processor on a
machine, then I put QM on a virtual server running on my 4 processor box and suddenly
I have 2 QM's running instead of 1.---not sure how performance would be, but my gut
from playing with QM is that the multiple QM's slightly slower QM's is better than 1 faster
QM---

But anyway...as a dedicated graphics monster only....

I would say it's worth it, if you hadn't bought the Vista, or had another box that could use the Vista or could still return.  But to have bought both...

http://www.newegg.com/Product/Product.aspx?Item=N82E16832116452

Here is my gut feelings on performance...

Windows 2008 Server seems about 25-35% faster than Windows 2003 Server on the
same processor you have.  That is my comparison, that I've been talking about.
(ignoring graphics cards which for my test were lower end PCIExpress, my newest
box has the 88000 GTX...and things went into overdrive on the GUI front)

Windows 2003, generally seemed about 10% faster than XP (it's desktop counterpart).

Most people seem to think that Vista is about 15-20% slower than XP.  But this is highly
subjective based on graphics card, memory, hard drives.  if you have sufficient resources
vista can really kick into gear, it just has to get past the minimum requirements.

One can mangle these numbers together however one wants, not sure if it comes out
to adding up.  I don't have a direct Vista to W2K8 comparison, but I'd say you are talking
a solid 25% faster, if not more.  But again, newer graphics card and crap loads of memory
also add up.

---

One big thing you want to do, in all cases, is make sure your bios has memory mapping
turned on for x64 bit OS's.  otherwise you won't see all 8 GB of RAM.  Highly dependent
on mobo how to do this (some will automatically others won't and you'll either see like
4 Gb or 7 GB)