[horde] Hardware/config recommendations for large rollout

[Kevin Konowalec]

We are looking to roll out horde/imp now that we have worked through  
all the config issues on our test box.  However, on a whim we opened  
the floodgates and pointed several hundred users at once to our box  
(IBM 325E w/1gig ram, single brain) and the load immediately shot  
through the roof, cratering the box.

So given that we have a high-water mark of about 2000+ concurrent  
users with our existing system, what would be the recommended  
hardware to be able to handle that kind of load?  I figure it would  
take 10 of these IBM boxes to handle the load if we used them.

I'm noticing that each httpd process is about 20+ megs... is that  
normal when using horde?  I don't currently have a php accelerator -  
would that reduce the process size?