From: | Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> |
---|---|
To: | Greg Smith <greg(at)2ndquadrant(dot)com> |
Cc: | "M(dot) D(dot)" <lists(at)turnkey(dot)bz>, pgsql-performance(at)postgresql(dot)org |
Subject: | Re: cpu comparison |
Date: | 2011-07-19 01:38:34 |
Message-ID: | CAOR=d=2ovPOhVtRa6Lk4c-B09B3dCCG7eyZt9DDLwSaR9SYLKg@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
On Mon, Jul 18, 2011 at 6:47 PM, Greg Smith <greg(at)2ndquadrant(dot)com> 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.
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 2011-07-19 01:59:56 | Re: BBU still needed with SSD? |
Previous Message | Andy | 2011-07-19 01:33:50 | Re: BBU still needed with SSD? |