On Tue, Jan 04, 2005 at 11:05:21PM +0100, Willy Tarreau scribbled: > Oh, while I'm at it, are you using hyperthreading, and if so, could you yes, as I wrote in the mail I've just sent - on one box which does NOT exhibit the problem... :) > disable it ? I have seen many cases where it degrades performances > significantly (eg: highly loaded user space network applications). We saw it in two cases as well, that's why in general we don't run with HT enabled (although we do test the boxes with it and if it behaves, we leave it on). best regards, marek