Mark Coccimiglio wrote:
Sounds like you are running into the hardware limitations of your systems PCI or "Front Side Bus" (FSB) and not necessarily an issue of asterisk. In short there is a limited amount of bandwidth on the computer's PCI Bus (33 MHz) and the FSB (100-800MHz). One thing to remember is that ALL cores and data streams need to share the PCI and FSB. Asterisk is very processor and memory intensive. At the extreme level of usage more cores won't help if data is "stuck in the pipe". So the performance planing you described would be expected.
Mark,
That is a great theory and I'd like to follow up on it. Do you know if the PCI or FSB buses are instrumented by Linux? If not, are you aware of any way to gather statistics about their utilization? I'd like to see if the numbers support your idea and, if so, which bus is saturated.
Let me add a little bit of extra information to this discussion. The CPU utilization does not flatten out at 50%. In fact, as more calls are added, Asterisk will eventually drive the idle percentage down to single digits with surprisingly few problems. If PCI or FSB bandwidth were the limiting factor, wouldn't the CPU utilization top out at the point that the available bandwidth was used?
Thank you, Matthew Roth InterMedia Marketing Solutions Software Engineer and Systems Developer _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
