On Thursday 15 April 2004 17:48, Konstantin Sobolev wrote:
On Thursday 15 April 2004 18:33, Justin Cormack wrote:
On Thu, 2004-04-15 at 15:26, Konstantin Sobolev wrote:
On Thursday 15 April 2004 18:00, Justin Cormack wrote:
hmm, odd. I get 50MB/s or so from normal (7200, 8MB cache) WD disks,
and Seagate from the same controller. Can you send lspci,
/proc/interrupts and dmesg...
Attached are files for 2.6.5-mm5 with highmem, ACPI and APIC turned
off.
ah. Make a filesystem on it and mount it and try again. I see you have
no partition table and so probably no filesystem. This means the block
size is set to default 512byte not 4k which makes disk operations slow.
Any filesystem should default to block size of 4k, eg ext2.
Very interesting!
created partition table,
kos sata # mkfs.ext2 /dev/sda1
[..skipped..]
kos mnt # cd /
kos / # mkdir wd
kos / # mount /dev/sda1 /wd
kos / # hdparm -t -a8192 /dev/sda
/dev/sda:
setting fs readahead to 8192
readahead = 8192 (on)
Timing buffered disk reads: 82 MB in 3.03 seconds = 27.02 MB/sec
kos / # mount | grep sda
/dev/sda1 on /wd type ext2 (rw)
kos / # hdparm -t -a8192 /dev/sda
/dev/sda:
setting fs readahead to 8192
readahead = 8192 (on)
Timing buffered disk reads: 206 MB in 3.02 seconds = 68.15 MB/sec
kos / # hdparm -t -a8192 /dev/sda
/dev/sda:
setting fs readahead to 8192
readahead = 8192 (on)
Timing buffered disk reads: 206 MB in 3.02 seconds = 68.18 MB/sec
So first time it gave the same loosy 27 MB/s and subsequent tests give
pretty good 68 MB/s! Why?
Time to CC ide/libata/block layer folks
Jeff Garzik <jgarzik@xxxxxxxxx>
libata man