hdparm shows poor performance on cached reads for PATA drive - users - Fedora Mailing-Lists

Monday, 26 November 2007

Hi all,

I have an older laptop (HP ze4400 series) with a PATA hard drive.
When I check hdparm -T /dev/sda in Fedora 7 or 8, it shows me 
performance of ~180MB/sec

When I use a boot CD (gparted/clonezilla) to check the speed (by the 
way, it uses the old style /dev/hdc, instead) - it tells me the 
performance is upward of 400MB/sec

The buffered speed seems about the same in either case at ~30MB/sec. 
(I've tried enabling/disabling various settings via hdparm, while in 
boot CD mode)

Why is this happening and is there a way to fix it (without reverting to 
/dev/hdc)?

Thanks!