On 12/05/2012 10:34 AM, Andrea Suisani wrote:
> [sorry for resuming an old thread]
>
> [cut]
>
>>>> Question is... will that remove the performance penalty of
>>>> HyperThreading?
>>>
>>> So I've added to my todo list to perform a test to verify this claim :)
>>
>> done.
>
> on this box:
>
>> in a brief: the box is dell a PowerEdge r720 with 16GB of RAM,
>> the cpu is a Xeon 5620 with 6 core, the OS is installed on a raid
>> (sata disk 7.2k rpm) and the PGDATA is on separate RAID 1 array
>> (sas 15K rpm) and the controller is a PERC H710 (bbwc with a cache
>> of 512 MB). (ubuntu 12.04)
>
> with postgres 9.2.1 and $PGDATA on a ext4 formatted partition
> i've got:
>
>> those are the results:
>>
>> HT HT SYSFS DIS HT BIOS DISABLE
>> -c -t r1 r2 r3 r1 r2 r3 r1 r2 r3
>> 5 20K 1641 1831 1496 2020 1974 2033 2005 1988 1967
>> 10 10K 2161 2134 2136 2277 2252 2216 1854 1824 1810
>> 20 5k 2550 2508 2558 2417 2388 2357 1924 1928 1954
>> 30 3333 2216 2272 2250 2333 2493 2496 1993 2009 2008
>> 40 2.5K 2179 2221 2250 2568 2535 2500 2025 2048 2018
>> 50 2K 2217 2213 2213 2487 2449 2604 2112 2016 2023
>
> on the same machine with the same configuration,
> having PGDATA on a xfs formatted partition gives me
> a much better TPS.
>
> e.g. pgbench -c 20 -t 5000 gives me 6305 TPS
> (3 runs with "echo 3 > /proc/sys/vm/drop_caches &&
> /etc/init.d/postgresql-9.2 restart"
> in between).
>
> Anybody else have experienced this kind of differences
> between etx4 and xfs?
>
> Andrea
>
>
>
I thought that postgreSQL did its own journalling, if that is the proper
term, so why not use an ext2 file system to lower overhead?
