On Mon, Jul 18, 2011 at 6:47 PM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > M. D. wrote: >> >> I'm a bit surprised as the x3450 has DDR3, while the E5335 has DDR2, and >> of course because of the cycle speed difference alone I would think the >> X3450 should beat the E5335. > > Try comparing them with stream-scaling to see what happens: > > https://github.com/gregs1104/stream-scaling > > You can't really test CPU performance in a simple way anymore; it varies > depending on the number of processes running at once. This test is the best > way I've found to show how that works. On a single thread, the X3450 may > not be significantly better than the E5535. But what should happen is that > total speed keeps going up as you add more threads on the newer system, > while the old DDR2 model stays as the same basic total. By way of example we have a server with dual 6 core opterons that runs on 667MHz memory and it maxes out the stream test with 8 threads, getting no faster as you add threads. OTOH, our 4x12 core opteron machines with 1333MHz memory and like 8 different channels to it, scales right up to 40 or more threads running the stream test. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
