Messages in this thread | | | Subject | Re: Bogomips on AMD X2 (was Re:) | From | Robert.Boermans@uk ... | Date | Wed, 21 Sep 2005 15:02:51 +0100 |
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> > I noticed that the bogomips results for the two cores on my machine are > > consistently not the same, the second one is always reported slightly > > faster, it's a small difference and I saw the same in a posted dmesg > from > > somebody else on the list. Which made me wonder: > > I guess it's a cache warming effect. Please show the numbers. > > Probably not, got this one from a web site, and on this one the first core > seems to be faster (can't check my own machine it's off and at home and > I'm at work.) The difference I get is similar, but always with the second > one faster. It's the same when using cat on /proc/cpuinfo. Oh and I saw it > on 2.6.11 and 2.6.12 as supplied with fedora core 4 myself. > > Calibrating delay using timer specific routine.. 4014.73 BogoMIPS > (lpj=8029470) ... > Initializing CPU#1 > Calibrating delay using timer specific routine.. 4005.37 BogoMIPS > (lpj=8010751)
Why do you think it cannot be a cache warming effect? -- vda
---------- Because with this one the first case was the faster one, that would need cache cooling :) But besides that, as far as I remember the actual loop is about 3 instructions long and will be cache hot in a time that you'd never notice in the end result.
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