Date: Fri, 12 Mar 2004 10:39:17 -0000 From: "Lawrence Farr" <freebsd-hw@epcdirect.co.uk> To: "'Artem Koutchine'" <matrix@itlegion.ru>, <freebsd-hardware@freebsd.org> Subject: RE: Multiprocessor system VS one processor system Message-ID: <20040312103909.1060D1551B@gunfright.epcdirect.co.uk> In-Reply-To: <002f01c4081c$bd720810$0c00a8c0@artem>
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I think you need to take into account everything else that changed as well, memory speed, disk controllers etc. Lawrence Farr EPC Direct Limited > -----Original Message----- > From: owner-freebsd-hardware@freebsd.org > [mailto:owner-freebsd-hardware@freebsd.org] On Behalf Of > Artem Koutchine > Sent: 12 March 2004 10:28 > To: freebsd-hardware@freebsd.org > Subject: Multiprocessor system VS one processor system > > Hi! > > I need to understand something very clear. > > As I understand FreeBSD (as of 4.9) runs one process > per one CPU. This means, that if i have dual systems > with 500Mhz CPUs one process can never run faster > than on a single 500Mhz CPU. However, if i substitute > those two CPUs with one 1000Mhz, that one process will run > twice as fast than on dual 500Mhz, however, to box will > become a bit less responsive, because in a dual box > when one CPU is loaded, another one may have some > spare time to respond. However, in case of very loaded > box both CPUs a extremely loaded and the box will > be as responsive as single 1000Mhz CPU box 100% loaded. > So, according to what i just said there is not real reason to > setup a dual CPU box under FREEBSD unless you want to > have 5000Mhz box, but there is no CPU with such speed, so > you put two 2500Mhz CPU in it and if you are running a lot > of processes with short run periods you will get overal > perfomance somewhere near 5000Mhz. However, when i > subsituted two 500Mhz CPUs with 1500Mhz one (even with > less 2nd level cache) on a heavy loaded web server i notice > that sites started to load faster. So, it seems as > one 3X Mhz CPU is faster that two X MHz CPUs, at least > for web server with sql base and many perl scripts. > > So, there are two questions: > 1) Am I right or am wrong? > 2) Does FreeBSD 5.X run one process only on one CPU > or it can run on thread of a process on one CPU and another > thread on another CPU? > > Regards, > Artem > _______________________________________________ > freebsd-hardware@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hardware > To unsubscribe, send any mail to > "freebsd-hardware-unsubscribe@freebsd.org" >
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