OT: Hard Drive Performance Advice

[Fairlight]

For over a year and a half, I've had issues with a Celeron 2.4GHz/512MB
setup, where we'd do video processing and the system was all but unusable
during such operations.  Ditto with burning DVD backups.  Launching
something as light as PuTTY used to take 5min, and typing was laboriously
slow (indescribably so) while, say, video conversions were taking place.

I just discovered something that...well, perhaps I should have known better
but I do gravitate towards software, not hardware.

It appears that I took several people's advice about Celerons and their
small cache being a bottleneck a bit too seriously.  The REAL problem is
adding a disk drive or DVD drive and not fully configuring things.

We set master/slave on the jumpers--I don't believe in cable select or
ambiguity.  Windows detected and used the hardware.  Never had a clue
anything was up.

Until today, when something offered to set DMA mode on my DVD drive,
detecting that it was in PIO mode.  That's when the dime dropped on a
serious issue that was entirely neglected.

When we received the system, apparently all but two slots of the four
(primary/secondary master and slave) were set to NONE, rather than AUTO.
When this happens, Windows will apparently detect the device, but will use
it in PIO mode.  PIO mode consumes gallopping ladlefulls of CPU time for
every tiny transfer to and from the drive, where Ultra DMA does not.

The solution was multifold:

1) Open the hardware manager, look at properties for your primary and
secondary IDE buses.  On the advanced settings tab, there'll be a section
for the master and the slave.  Likely they're already set to "DMA if
available".  However, look at the Current Transfer Mode.  If it's PIO, you
have issues that are dragging your system's performance down dramatically.
If everything is currently in Ultra DMA mode, you're fine, you're done.
If you see PIO mode, go on to step 2:

2) Reboot into the BIOS and make sure your devices are actually detected
-there-, listed, and that they're allowed to use DMA mode.  In our case, in
an Award BIOS on an ASUS board, two of the drives were totally undefined as
NONE.  Switched to AUTO and they came up as the appropriate models.  Save
changes and exit BIOS.

3) Let it boot into Windows, recheck what you looked at in step #1.  If
they're all reading Ultra DMA for your current transfer mode, you should
now have significant performance increases.

I have to wonder, because I surely didn't know--I guess I assume the BIOS
was set to autodetect, and Windows listing it despite the fact the BIOS
didn't autodetect completely didn't help tell me--I didn't know that this
kind of incomplete detection was actually possible, nor have any idea of
the impact it would have on the system.  I have to wonder just how many
people add drives to their systems without knowing about this and suffer
really poor performance because of it.

Given some of the inexplicable speed issues that have been reported with
filePro over the years (including after system upgrades), I thought I'd 
share this experience and try to help anyone else that might not be aware
of this pitfall.

Boy, do I feel stupid.  But technically, Windows shouldn't be detecting,
reporting, and using a device that the BIOS isn't configured to detect.
That would have been a dead giveaway to me and had this fixed at the time
the newer drives were installed.  Pity it was hidden and caused me to blame
the CPU.  We can now use the system pretty normally while processing video,
and CPU usage used to be pegged at 100% while reading from DVD to disk,
where now it's only at 53% on average.  Hell of a difference.

I can only imagine what it would do to/for record lookups performance in a
database context.  PIO is a -lot- of CPU overhead.

If you've added a hard drive lately, or even think it should be running
faster than it is on a system that you didn't install yourself and know how
it was configured (or did yourself, but like me did not know about this
issue), check your settings--you might boost performance noticeably.

Bests,

mark->
-- 
Fairlight->   ||| "Old men sometimes get a bit       | Fairlight Consulting
  __/\__      ||| short-tempered; I'm a bit busy     |
 <__<>__>     ||| now--go boil your head!" --Young   | http://www.fairlite.com
    \/        ||| Mister Grace, "Are You Being       | info at fairlite.com
              ||| Served?"                           |