These boards seem more popular with
Linux users. Why?
Server and server motherboard vendors are usually very careful to support Linux, at least Red Hat and SuSE, since that is almost 1/4 of their market. The percentage of desktop market is much smaller (though the overall quantity is probably much higher).
AMD and Intel both have server CPUs as well. Some question, what's the difference?
Until recently, AMD systems enjoyed a much faster memory interface that was more suitable for servers. Since the Nehalem architecture reached servers, Intel has surpassed AMD. Intel's latest CPUs are more efficient in their instructions per clock ratio. AMD maintains their standing through careful pricing and performance-per-watt.
Unless you absolutely need the fastest server processor available, AMD server systems remain competitive, but Intel (for the moment) rules the high end.
Can I get a motherboard without on
board raid and audio? I wanted to get
a hardware raid controller and a PCI
audio card. I thought a server
motherboard would be cheaper and not
have these "extras", since who wants
an audio card on a server?
Server motherboards generally support ECC memory (self-correcting on errors), and may support things like dual power supplies, and usually have at least two Ethernet ports, and a higher end warranty, all of which drives the price up.
but I don't want to rule out the possibility of installing windows
Some server motherboards are only qualified for Windows Server 2003 and up. Others (targeted more at the CAD workstation market) are validated for 64 bit Windows Vista and/or 7.
Is it a good idea to buy a "server motherboard" and play games on it, or are desktop boards better value for this?
There is such a wide variety of desktop, workstation, upright server, and rack mount server motherboards out there, chances are you can find whatever compromise you are looking for, except for the price factor. Higher end equipment costs more, unless you buy used or obsolete, that is not going to change.
Best Answer
Because the use fundamentally different bus architectures; see HyperTransport and QuickPath Interconnect for the details. Physical similarities in the arrangement of pins, etc, are mostly down to the physical realities of building a CPU dictating much of the form.
At a larger scale, the answer is: because they believe they have more to gain from incompatibility, for business reasons, than they do from compatibility.