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