[CentOS] Strangely slow disk

[Yves Bellefeuille]

On Sunday 04 December 2011 19:38, Timothy Murphy wrote:

> The "slow disk"
> [tim at helen ~]$ sudo hdparm -t /dev/sdb
> /dev/sdb:
>  Timing buffered disk reads:  168 MB in  3.00 seconds =  55.98 MB/sec
> -----------------------------------
> Another disk on the same machine
> [tim at blanche ~]$ sudo hdparm -t /dev/sda
> /dev/sda:
>  Timing buffered disk reads: 146 MB in  3.01 seconds =  48.57 MB/sec

Here are my results with a PATA drive and a SATA drive:

[root at poontang ~]# hdparm -t /dev/hda

/dev/hda:
 Timing buffered disk reads:  172 MB in  3.02 seconds =  56.97 MB/sec
[root at poontang ~]# hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads:  300 MB in  3.01 seconds =  99.66 MB/sec

Your results are similar to what I get with my PATA drive, so I agree 
with Ho Chaw Ming that you should check that AHCI is selected.

-- 
Yves Bellefeuille <yan at storm.ca>
"La Esperanta Civito ne rifuzas anticipe la kunlaboron de erarintoj, se
ili konscias pri sia eraro." -- Heroldo Komunikas, n-ro 473.