Re: Intel 710 pgbench write latencies

On 2011-11-02 16:16, Yeb Havinga wrote:
> On 2011-11-02 15:26, Merlin Moncure wrote:
>
>> I would keep at least 20-30% of both drives unpartitioned to leave the
>> controller room to wear level and as well as other stuff.  I'd try
>> wiping the drives, reparititoing, and repeating your test.  I would
>> also compare times through mdadm and directly to the device.
>
> Good idea.

Reinstalled system - > 50% drives unpartitioned.
/dev/sdb3              19G  5.0G   13G  29% /ocz
/dev/sda3              19G  4.8G   13G  28% /intel
/dev/sdb3 on /ocz type ext4 (rw,noatime,nobarrier,discard)
/dev/sda3 on /intel type ext4 (rw,noatime,nobarrier,discard)

Again WAL was put in a ramdisk.

pgbench -i -s 300 t # fits in ram
pgbench -c 20 -M prepared -T 300 -l  t

Intel latency graph at http://imgur.com/Hh3xI
Ocz latency graph at http://imgur.com/T09LG