Date: Fri, 12 Nov 1999 22:58:09 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Simon Shapiro <shimon@simon-shapiro.org> Cc: freebsd-arch@freebsd.org Subject: Re: I/O Evaluation Questions (Long but interesting!) Message-ID: <Pine.BSF.4.10.9911122245070.17251-100000@alphplex.bde.org> In-Reply-To: <38290C04.8FC73862@simon-shapiro.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 10 Nov 1999, Simon Shapiro wrote: > Bruce Evans wrote: > > > We run circles around NT in the Random I/O department, > > > but take a beating in the sequential I/O arena; > > > For about the same hardware, they do 98 MB/Sec, > > > I cannot get more than 45. > > > > I've always though FreeBSD has the opposite problem. > > Nope. I am getting 167MB/Sec for random block device. I didn't believe this, but later mail explains that it must be due to buffering. > We are almost nine times faster on random WRITE (and I > am comparing RAW I/O here to buffered there), twice as > fast on random READ (again our RAW vs. their buffered. > > If you compare our block perfromance to theirs, we are > almost fourty times faster. This is almost certainly due to our buffer cache actually working for the i/o mix in your test. Having the buffer cache unified with vm helps here by removing arbitrary limits on the effective size of the buffer cache. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.10.9911122245070.17251-100000>