On 09/18/2014 08:09 AM, Mkrtchyan, Tigran wrote: >>> 9.4beta2: >>> > > >> > ... >> > >>> > > 0.957854 END; >>> > > >> > >> > Looks like IO. > Postgres internal IO? May be. We get 600MB/s on this SSDs. While it's possible that this is a Postgres issue, my first thought is that the two SSDs are not actually identical. The 9.4 one may either have a fault, or may be mostly full and heavily fragmented. Or the Dell PCIe card may have an issue. You are using "scale 1" which is a < 1MB database, and one client and 1 thread, which is an interesting test I wouldn't necessarily have done myself. I'll throw the same test on one of my machines and see how it does. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance