citrix4Performance on (or lack of) x64 issues
| Adam Shackleford | We have begun migrating users from 32bit to 64bit OS and Citrix. All looks great…until the user count reaches 40 sessions (not users). The users are running a web based app that spawns a few VB apps from a file share. (I know…don’t ask). Anyway, on the 32 bit servers which are Dual 2.4s with 4GB RAM I can run 40 sessions and the CPU total is running around 60% but it appears that we max the kernel memory issue because free RAM is around 1-1.5GB. I assumed this is contention between users RAM and kernel RAM.
The new servers are x64 with Dual Dual core 1.6’s with 8GB RAM. With 20 sessions the avg CPU usage is running around 15-20% as the 25th - 40th sessions are started, the CPU total begins to climb rapidly. What is interesting is when all 4 CPUs are “pegged” and using Systrack, I check what is going on, I find that priviledged CPU time (kernel CPU) is running at 90-95% and user CPU time is the remaining 5-10%. I understand that there is a little more overhead on x64, and I also understand that running 32bit apps uses a bit more overhead, but kernel CPU running at 90% when the session count reaches 40 makes no sense. We began moving to x64 in hopes of reducing the number of servers and also providing a more robust platform for user experience. At this rate I will have to use the same number of servers for the same number of users. %26lt;SIGH%26gt; Checking this forum before opening a Citrix call. TIA Adam |
