On Wed, Nov 17, 2010 at 3:24 PM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > Scott Carey wrote: >> >> Did you recompile your test on the RHEL6 system? > > On both systems I showed, I checked out a fresh copy of the PostgreSQL 9.1 > HEAD from the git repo, and compiled that on the server, to make sure I was > pulling in the appropriate kernel headers. ÂI wasn't aware of exactly how > the kernel sync stuff was refactored though, thanks for the concise update > on that. ÂI can do similar tests on a RHEL5 system, but not on the same > hardware. ÂCan only make my laptop boot so many operating systems at a time > usefully. One thing to note is that where on a disk things sit can make a /huge/ difference - depending on if Ubuntu is /here/ and RHEL is /there/ and so on can make a factor of 2 or more difference. The outside tracks of most modern SATA disks can do around 120MB/s. The inside tracks aren't even half of that. -- Jon -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance