On 11/18/05 5:00 AM, "Dave Cramer" <pg@xxxxxxxxxxxxx> wrote:
>
> Now there's an interesting line drawn in the sand. I presume you have
> numbers to back this up ?
>
> This should draw some interesting posts.
OK, here we go:
The $1,000 system (System A):
- I bought 16 of these in 2003 for $1,200 each. They have Intel or Asus motherboards, Intel P4 3.0GHz CPUs with an 800MHz FSB. They have a system drive and two RAID0 SATA drives, the Western Digital 74GB Raptor (10K RPM). They have 1GB of RAM.
- A test of write and read performance on the RAID0:
[llonergan@kite4 raid0]$ time dd if=/dev/zero of=bigfile bs=8k count=250000
250000+0 records in
250000+0 records out
real 0m17.453s
user 0m0.249s
sys 0m10.246s
[llonergan@kite4 raid0]$ time dd if=bigfile of=/dev/null bs=8k
250000+0 records in
250000+0 records out
real 0m18.930s
user 0m0.130s
sys 0m3.590s
So, the write performance is 114MB/s and read performance is 106MB/s.
The $6,000 system (System B):
- I just bought 5 of these systems for $6,000 each. They are dual Opteron systems with 8GB of RAM and 2x 250 model CPUs, which are close to the fastest. They have the new 3Ware 9550SX SATA RAID adapters coupled to Western Digital 400GB RE2 model hard drives. They are organized as a RAID5.
- A test of write and read performance on the RAID5:
[root@modena2 dbfast1]# time dd if=/dev/zero of=bigfile bs=8k count=2000000So, the question is: which of these systems (A or B) can scan a large table faster using non-MPP postgres? How much faster would you wager?
2000000+0 records in
2000000+0 records out
real 0m51.441s
user 0m0.288s
sys 0m29.119s
[root@modena2 dbfast1]# time dd if=bigfile of=/dev/null bs=8k
2000000+0 records in
2000000+0 records out
real 0m39.605s
user 0m0.244s
sys 0m19.207s
So, the write performance is 314MB/s and read performance is 404MB/s (!) This is the fastest I’ve seen 8 disk drives perform.
Send your answer, and I’ll post the result.
Regards,
- Luke
