On Mon, Mar 3, 2008 at 5:11 PM, Greg Smith <gsmith@xxxxxxxxxxxxx> wrote: > On Mon, 3 Mar 2008, alan bryan wrote: > > >> pgbench -c 100 -t 1000 testdb > > > tps = 558.013714 (excluding connections establishing) > > > > Just for testing, I tried turning off fsync and got: > > > tps = 4061.662041 (excluding connections establishing) > > This is odd. ~500 is what I expect from this test when there is no write > cache to accelerate fsync, while ~4000 is normal for your class of > hardware when you have such a cache. Since you say your 3Ware card is > setup with a cache and a BBU, that's suspicious--you should be able to get > around 4000 with fsync on. Any chance you have the card set to > write-through instead of write-back? That's the only thing that comes to > mind that would cause this. > > -- > * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD > According to 3dm2 the cache is on. I even tried setting The StorSave preference to "Performance" with no real benefit. There seems to be something really wrong with disk performance. Here's the results from bonnie: File './Bonnie.2551', size: 104857600 Writing with putc()...done Rewriting...done Writing intelligently...done Reading with getc()...done Reading intelligently...done Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done... -------Sequential Output-------- ---Sequential Input-- --Random-- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU 100 9989 4.8 6739 1.0 18900 7.8 225973 98.5 1914662 99.9 177210.7 259.7 This is on FreeBSD 7.0-Release. I tried ULE and 4BSD schedulers with no difference. Maybe I'll try FreeBSD 6.3 to see what that does? -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your Subscription: http://mail.postgresql.org/mj/mj_wwwusr?domain=postgresql.org&extra=pgsql-performance
