That works out at a load average of about 18 per cpu, which is of course workable as you point out, however stuff like sendmail would bulk when it reaches 12. P. Lamar Owen wrote: > On Wednesday 01 March 2006 13:45, Peter Farrow wrote: > >> You need to check out whether the system is waiting on IO, on the >> version of top on Centos 4.2 it doesn't show IO wait on the display, but >> on the RH enterprise shipping version it does. >> > > >> A load average of 9 is getting high, you expect would services like >> sendmail to stop listening once the system load average gets to 12. >> > > As a data point, on my Sun E6500 during load testing a few months back, under > Aurora SPARC Linux (I would expect similar performance from CentOS SPARC) I > was pulling a load average of 250+ with little interactive degradation > (command line mode). The E6500 had 14 CPU's and 16GB of RAM at the time, and > was serving an ab load (apache bench) of 256 concurrent requests to a Koha > integrated library system backend, over a total of 2.5 million requests. > Every page hit the database at least twice, from Perl. System at that load > average was serving 6 pages per second; at a concurrency of 1, system served > 4 pages per second, so performance increased as load did. I would have hit > it with more concurrency, but httpd was compiled with a 256 connection max > limit. >