David C. Rankin wrote:
Listmates,
I ran a comparison on an old file server just to check disk performance of the backup machine. I compared it to a new machine and the difference validates Mohr's law:
[AMD K62-450 w/2 20G IBM Deskstar 7200 rpm drives]
sudo hdparm -tT /dev/sda /dev/sda: Timing cached reads: 72 MB in 2.00 seconds = 35.94 MB/sec Timing buffered disk reads: 26 MB in 3.09 seconds = 8.41 MB/sec
[AMD Phenom 9850 w/2 500G Seagates in RAID1]
/dev/sda: Timing cached reads: 3504 MB in 2.00 seconds = 1751.75 MB/sec Timing buffered disk reads: 188 MB in 3.02 seconds = 62.33 MB/sec /dev/sdb: Timing cached reads: 3494 MB in 2.00 seconds = 1746.89 MB/sec Timing buffered disk reads: 200 MB in 3.01 seconds = 66.53 MB/sec
/dev/dm-0: Timing cached reads: 3432 MB in 2.00 seconds = 1716.32 MB/sec Timing buffered disk reads: 194 MB in 3.02 seconds = 64.27 MB/sec
The Software RAID penalty -- virtually non-existent as far as hdparm is concerned.
That is probably due to getting rid of the pci bus. Here's a hardware raid (3ware 9650SE, 5 x 750 GB Seagate SATA2): mordor:~ # hdparm -tT /dev/mapper/system-var /dev/mapper/system-var: Timing cached reads: 13236 MB in 2.00 seconds = 6626.75 MB/sec Timing buffered disk reads: 1130 MB in 3.00 seconds = 376.05 MB/sec -- Sandy List replies only please! Please address PMs to: news-reply2 (@) japantest (.) homelinux (.) com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org