Date: Sun, 20 Nov 2011 15:21:16 -0700 From: Stephen John Smoogen <smooge@...il.com> To: john-users@...ts.openwall.com Subject: Re: OpenMP not using all threads On 19 November 2011 21:35, Stephen Reese <rsreese@...il.com> wrote: > On Sat, Nov 19, 2011 at 11:13 PM, Solar Designer <solar@...nwall.com> wrote: >> On Sat, Nov 19, 2011 at 10:38:30PM -0500, Stephen Reese wrote: > I confirmed that there are 8 threads (4 cores) in the processor > http://ark.intel.com/products/40201/Intel-Xeon-Processor-L5520-%288M-Cache-2_26-GHz-5_86-GTs-Intel-QPI%29 > I asked Linode and their response was there are four cores hence I am > only going to see four entries in /proc/cpuinfo. Maybe they have > hyper-threading disabled (I asked and did not receive a specific > response). Most (if not all) Linode systems are virtualized systems which I believe normally don't do well with hyperthreading. For high compute virtualization you usually need systems with cpu-pinning and such to get the performance that you get from bare metal. -- Stephen J Smoogen. "The core skill of innovators is error recovery, not failure avoidance." Randy Nelson, President of Pixar University. "Let us be kind, one to another, for most of us are fighting a hard battle." -- Ian MacLaren
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