17 Jul
2004
17 Jul
'04
5:09 p.m.
Last Saturday 17 July 2004 12:53, Malcolm Baldridge was like:
If you're "on the borderline" with
xruns, you might gain something by
tuning your IDE driver with a smaller or larger -m setting. Try -m1, -m4,
-m8, or -m16.
One of my harddrives actually seems to prefer -m32
Finally, this may sound weird and voodoo, but make
sure your IDE cables
aren't too twisted or molested. Cable CRC errors do happen and they cause
abrupt transfer speed aberrations.
No, I've heard it enough times. Actually, this may well be worth me checking.
I have one of those stupidly small cases, it's pretty hard not to twist the
IDE cables a bit. I know, I am a compulsive cable straightener / untangler -
intuitively, tangled cables carrying electrical signals has never seemed like
a good idea.
If you install smartmontools (S.M.A.R.T. drive
logging/diagnostic tool),
you can inquire of cabling CRC errors and note whether or not you seem to
be getting alot of them in your system.
I have yet to meet a post-440FX (Pentium era) chipset whose Linux IDE
driver 'sperformance was not radically improved with a massive reduction in
CPU utilisation during heavy disk I/O when the IDE driver was tuned with
-c1 -u1 -d1 versus one which was NOT tuned. -c1 may not provide any
tangible benefit, but -d1 definitely does, and -u1 gets you released from
IRQ-hold-off states within the driver a bit earlier. Modern kernels built
with specific IDE chipset support are doing a better job of configuring
these with good defaults. Verify it with: hdparm -v /dev/hda
-u1 has the most tangible benefit, I don't know if that really applies to
music, but it does mean that the system can do something else at the same
time as redrawing the screen, which does give an immediately noticeable
change.
The AGNULA system that I use now comes with these hdparm settings as default,
so I probably don't need to look at that again.
Last Saturday 17 July 2004 14:58, RickTaylor(a)speakeasy.net was like:
You do have to be careful with it. You can fry your
drive.
Yep, don't try this at home, kids. At least back well up and RTFM first. I did
it gently and then backed off at the first signs of disk misreads. Me not
silly ;-)
cheers
tim hall