On Wed, Apr 23, 2008 at 11:33 PM, Sonia Hamilton <[EMAIL PROTECTED]> wrote: > A question about uptime. My understanding of the load average figures is > that a figure less than 2.0 on a 2 CPU machine means the CPUs don't have > more work than they can keep up with (on average). > > How is this figure (1 per CPU) affected on multicore CPUs? What about > multi-threaded CPU's?
As far as I remember, back when multi-threading just popped up (before multi-core came) the word was to regard each thread as a CPU for load average proposes, even though they were running on the same CPU. The rule of thumb I inherited decades ago and always worked for me when I cared about it, is to feel ok with up to 2xCPU cores (i.e. two processes per core/thread/whatever), AfC's anecdote about Amazon specific case aside. The funny thing these days is that with the amount of cores you can put on single boards today it's easy to clog the data paths (bus, memory, disks, network) so don't forget to look at these too. --Amos -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
