Message-ID: <4F6915FD.804@auul.pri.ee>
Date: Wed, 21 Mar 2012 01:42:53 +0200
From: Imre Oolberg <imre@auul.pri.ee>
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To: pgsql-admin@postgresql.org
Subject: deciding between amd and intel processor
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Hi!

My comerade has to decide for his so to say generic and a bit=20
unpredicted PostgreSQL needs for web applications between Intel and AMD=20
based server. For now it has been coming down to these processor choices

1. Dell PowerEdge R810 which has 2 x Intel=C2=AE Xeon=C2=AE E7=C2=AD-4830=
 2.13GHz, 24M=20
cache 6.4 GT/s QPI, Turbo, HT, 8C, 1066MHz Max Mem processors

as i see this makes total of 2 x 16 cores (or 2 x 16 threads) amd in=20
total of 2 x 24 MB L2 cache

2. Dell PowerEdge R815 4 x AMD Opteron 6272, 2.1GHz, 16C, Turbo
CORE, 16M L2/16M L3, 1600Mhz Max Mem processors

as i see this makes total of 4 x 16 cores and in total of 4 x 16 MB L2 ca=
che

Other computer components are quite similar

- 128 GB 1333 dual ranked lv rdimm MHz memory for AMD
- 128 GB 1066 dual ranked lv rdimm MHz memory for Intel
- PERC H700 Integrated RAID Controller, 1GB NV Cache
- 4 x 600GB 10K RPM SAS 6Gbps 2.5in Hot=C2=ADplug Hard Drive
- Broadcom NetXtreme II 5709 Gigabit Ethernet NIC

Based on dell.com AMD variant comes about $14 k and Intel $17 k.

And i got following questions in mind

1. do you suggest this Intel or this AMD configuration taking also into=20
account price? while it seems obvious to go with AMD so to say=20
price-wise are there some hidden rocks behind the surface going with AMD=20
(like L2 cache usage, overall system stability)?

2. if it makes much sence to ask like this what could be considered on=20
normal postgresql workload (with web applications) reasonable balance=20
between cpu cores and memory system has?

3. it is intended to use debian on this system, now squeeze and some day=20
wheezy, both hardwares most probably match quite well with debian and=20
postgresql?

4. it is intended not to use virtualization (KVM or Xen) but if needed,=20
then just use different pg clusters as in pg_lsclusters, and controlling=20
resources for each with shared_buffers etc, or should virtualization=20
rather be considered?

5. i know that with four physical disks databases are generally=20
recommended to use raid10 , but what would be recommended raid setup=20
with six drives?

I would be thankful if somebody would find time to answer this letter.


Best regards,

Imre