A good Xserve set up would be 2 x 2.26Ghz Quad Xeons
128GB SSD Boot drive
3 x 1TB ADMs with the hardware RAID card
Dual PSUs
Comes to about £4639
Have a look at Dell's website, the equivalent server specification-wise is the
Poweredge R610
with 3 x 300GB SAS RAIDed drives and Windows 2008 25 CAL server
comes to roughly £7500
I know which one I'd prefer! And negotiating Dell's server configuration page is... challenging.
This is hardly a fair comparison. While I do love Apple hardware, the Xserve is by no means blowing the competition out of the water when it comes to cost. For instance, the base configuration for the Dell R610 starts at $1749, a cool $1250 below the base Xserve. That also includes a 3 year ON-SITE hardware warranty. A more accurate model-to-model comparison between the base Xserve and the Dell R610 would be the following:
Dell configured with Xeon 5520 (2.26 x 4 core, +$300), 6GB (3x2GB) memory (+$185), rack kit ($149), 146GB 10K SAS drive (+$50), DVD +/- RW (+$69). Add your favorite linux enterprise OS (e.g. CentOS which costs nothing) for a total of $2492.
VS.
Apple configured with 6GB (3x2GB) memory (+$150), display port to DVI cable (+$29), AppleCare Support 3-year (+$950). This obviously comes with OS X Server Unlimited which has a retail of $999 but can be picked up on Ebay for ~$300 - $400. Total cost? $4128. Or more than $1600 more than the Dell.
What are the differences between these two "similar" configurations? 1. OS. This is obviously the selling point for Apple. If you want OS X server you have only one option. Comparisons to a "25 client Windows" license at $3700 might not be directly applicable as I don't know what that grants you in the Windows world. The "unlimited" client aspect of OS X only refers to file sharing, not logged in users, etc. I think that many of the more recent Linux server OS's compare well and most can be obtained for less than $1000 with a one year support contract, if not free (CentOS). Ultimately the decision is in the hands of the end-user, but from a purely hardware standpoint you can do much better than blindly buying an Apple rackmount.
Two other quick comparisons without the details but following the same methodology:
8 x 2.93 GHz: Dell ($5455), Apple ($7328). Difference: ~$1900.
8 x 2.66 GHz: Dell ($4455), Apple ($6128). Difference: ~$1700.
Conclusion: Apple values their OS X Server and hardware design at about $1700. If you want OS X server, get Apple. If you're just going to install linux (like a post earlier in this thread alluded to, you can do that for much cheaper elsewhere). (As a side note I think OS X server is worth the extra cost, I'm just waiting for Snow Leopard before I upgrade our company computers).