Hardware Analysis has done a "how-to" about building a "high-perf" web server:
http://www.hardwareanalysis.com/content/article/1549/
Of course i rushed to read it, hoping to get real good info.
Bad luck - this is an informercial.
1 - the architecture choice. Intel (or AMD) based machines are not suited to "high-performance" web serving. Sun or IBM mainframes (or even mid-range servers) are still far ahead in terms of I/O bandwidth, scalability, response times. Oh and compare manpower needed to maintain a 500-hosts x86 cluster against a (more expensive, similar performance) pair of Sun mainframes.
2 - the I/O subsystem. They base their choice on arguments like 'adaptec RAID controllers suck' (which is true btw) - not a reason to discard SCSI RAID altogether. More BS like 'SCSI runs hot' which is no longer true nowadays (15K drives dont run hotter than IDE 7.2K). Try to hot-swap IDE disks... Or to run RAID 50...
3 - the OS choice. Linux is a good choice indeed, but basing the comparison on W2K pro (which is the *DESKTOP* version, not the server) ain't really fair. Besides Redhat distro aint really suited to server environment (less than average security, hard to strip down etc.)
4 - as told by a few slashdot readers - at ~1000 visitors their server was already sluggish, at ~2000 it was nearly dead, and after that it was totally slashdotted. Bye bye, "high-performance" web server...
I could carry on but i feel it's enough.
*PLONK*
(sound made by the "ignore web site" button - this one has joined THG and [H] in my blacklist)