>  > > On a related note, what's the consensus on enabling hyperthreading on
>  > > a CentOS system?  Good, bad, indifferent?  The systems will be used
>  > > as developer workstations.
>  >
>  > If it is a 100% workstation only (no mysql, postgres etc), then it is
>  > ok to use it. Otherwise, you are asking for trouble.
>

Four x86_64 systems, all dual Xeon with hyperthreading enabled: one dedicated MySQL server, two web servers, one combined web + MySQL server, running CentOS 4.3 (2 systems) and Debian (2 systems)
One x86 system, also dual Xeon with hyperthreading enabled, web server (Debian).

Everything has worked flawlessly so far.