Re: IDE disk slow? There's help...

From: safemode (safemode@voicenet.com)
Date: Fri Oct 20 2000 - 14:44:00 EST


On Fri, 20 Oct 2000 15:34:04 Dmitry Pogosyan wrote:
> safemode wrote:
>
> > That's what i was thinking, but 30MB/s seems to be quite an
> exaggeration.
> > On my
> > Intel Corporation 82371AB PIIX4 IDE (rev 01), ide chipset my master
> (10.2GB
> > maxtor 7200rpm UDMA66) drive i get ~15-16MB/s and on my slave (same
> > interface, 20.1GB maxtor 7200rpm UDMA66), i get ~13MB/s. This goes
> against
> > logic as the bigger the drive the faster the transferrate should be,
> and
> > it's about half of your estimate of Michael's 40GB. Is this due to the
> > slow disk access of 2.4.0-test10-preX ? Or am i experiencing a bug
> here?
> > Both drives are operating at UDMA33 mode
>
> Isn't it this a reason ? You are not using UDMA66

Actually, the difference between UDMA33 and UDMA66 mode occurs mostly in
the cache, I should be getting in the upwards of 20MB/s with UDMA33, the
first drive is gettings speeds i would expect, but the second is
drastically slower even though logic of ide drives dictate it should be
going faster since it is bigger. At least this is the general pattern you
see with ide drives.

 
>
> > (according to hdparm) and both
> > drives are set to using 32bit, dma, 16 sector read ahead and 16 sector
> > multi-access mode. I've posted results i've gotten from bonnie and
> > bonnie++ before, in all cases, the performance seems to be lacking for
> the
> > kind of hardware i have.
>
> I have 17-18 MB/sec on my Quantum Fireball 6.4GB (5400 rpm)
> drive attached to UDMA33 and 14-15 MB/sec on another, also 5400 rpm
> (guess Samsung) drive. Both in -c1 -d1 -m16 mode.
>
> Ah, sorry, this is with ancient 2.2.5 kernel
>
>
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon Oct 23 2000 - 21:00:17 EST