Well they look the same, but they will have different versions of components. There were some massive difference in HAL between R1 and R2. I remember there was an issue running XP under Hyper-v. It was dog slow and CPU hog. Because of some HAL issues XP was almost unusable whereas 2003 R2 was working perfectly fine.

Me too. I know disc 1 of r2 and 2003 x64 sure looked the same… Now I need to look to see if I still have access to 2003 x64 & 2003 x64 r2..

I thought the R2 edition was basically an add-on to plain 2003 adding things like SUA.

Technically this is correct, except, Server 2003 x64 had R2 edition that XP x64 does not. The R2 edition is much improved and has support for much never hardware.

Sure people install 2008 because of hardware/.net stuff, but really I haven’t seen any compelling features. I guess the x64 stuff on 2003 & SQL 2005 was all I needed.

XP x64 only ‘sucked’ because MS pulled the rug out from under it when Vista shipped.
What is fun is that this is why officially XP x64 and Server 2003 x64 have different support lifecycles despite the fact that they are really based on the same codebase. And they allow only a minimum of two years after a new version release before the previous version goes into extended support (which lasts for another five years). And of course this is despite the fact that Vista RTM had plenty of problems, and Server 2008 is based on Vista SP1 which fixed many of them.

I thought you mean they completely failed to catch on, which isn’t true.

Have you seen any compelling reason to use them? I sure haven’t.

yep!

“XP” x64 is just another edition of Server 2003 x64.