Re: Inserting 8MB bytea: just 25% of disk perf used? - Mailing list pgsql-performance

From fkater@googlemail.com
Subject Re: Inserting 8MB bytea: just 25% of disk perf used?
Date
Msg-id 20100119101607.GA2200@comppasch2
Whole thread Raw
In response to Re: Inserting 8MB bytea: just 25% of disk perf used?  ("fkater@googlemail.com" <fkater@googlemail.com>)
Responses Re: Inserting 8MB bytea: just 25% of disk perf used?  (Ivan Voras <ivoras@freebsd.org>)
List pgsql-performance
fkater@googlemail.com:

> I'll try to execute these tests on a SSD
> and/or Raid system.

FYI:

On a sata raid-0 (mid range hardware) and recent 2x 1.5 TB
disks with a write performance of 100 MB/s (worst, to 200
MB/s max), I get a performance of 18.2 MB/s. Before, with
other disk 43 MB/s (worst to 70 MB/s max) postgres came to
14-16 MB/s.

So, I conclude finally:

(1) Postgresql write throughput (slowly) scales with the
harddisk speed.

(2) The throughput (not counting WAL doubling data) in
postgresql is 20-25% of the disk thoughput.


I want to thank you all for the very good support!

 Felix



pgsql-performance by date:

Previous
From: Scott Carey
Date:
Subject: Re: Inserting 8MB bytea: just 25% of disk perf used?
Next
From: "fkater@googlemail.com"
Date:
Subject: Re: Inserting 8MB bytea: just 25% of disk perf used?