[NTLUG:Discuss] Hard drive question

[Dan Carlson]

The ATA drives that support the various UDMA modes are all supposed to be
backward compatible with all the earlier modes.  That is, if you have an
ATA 100 drive attached to an ATA 66 or 33 controller, the drive is supposed
to fall back to the slower mode and it is all supposed to work, just at the
slower speed.

There have always been little compatibility problems where if you plugged
drives from two different manufacturers in as master and slave on a given
IDE channel, they may or may not get along with one another.  As near as I
can tell, this has nothing to do with the UDMA modes that are supported.

Whether or not DMA is enabled on a drive (and which mode is enabled) can
depend on both BIOS settings and your linux configuration.  Some older
distros used to enable DMA by default; most modern distros have stopped
doing that to avoid the problems that can result.  Some distros allow you
to enable "hard drive optimization" at install time.  For those that don't,
you can add the appropriate hdparm -d1 command to the appropriate boot
script.  You may need to use the -X option to force a particular DMA mode.
It is also a good idea to turn on 32-bit i/o with the -c1 option.

Even if your BIOS can't see all of your 120 GB drive, that shouldn't affect
linux's ability to see all of it.  Just put your kernel (i.e. your /boot
partition) in the portion the BIOS can see below cylinder 1024 (since your
1998 BIOS probably doesn't do LBA32) and linux should work just fine.

PCI IDE controllers are a good option, if you have available slots.
Personally, I've had better luck with Promise controllers than with
Highpoint controllers.

As an aside, things start to get interesting now with ATA 133 just coming
out, supposedly the last wide parallel IDE interface before serial IDE
comes out.  The problem with ATA 133 is that it is more than capable of
fully saturating a 32-bit 33 MHz PCI bus.  The only way to take full
advantage of it and still have bandwith left over for other bus mastering
devices is to run it on its own separate bus or on a 64-bit  and/or 66 MHz
PCI bus.

Dan Carlson

----- Original Message -----
From: "Fred James" <fredjame at concentric.net>
To: "Discuss North Texas Linux Users Group" <discuss at ntlug.org>
Sent: Thursday, August 29, 2002 6:18 AM
Subject: [NTLUG:Discuss] Hard drive question


> Will I be able to run an ATA/100 hard drive on my 1998 motherboard?
> Would upgrading the BIOS be of any benefit?
> Does upgrading the BIOS dangerous in terms of OS and data already on the
> hard drive?
>
> Elitegroup P6BX-A+ motherboard
> Award BIOS v4.51PG
>
> (the following information is from:
> <http://www.hardwarecentral.com/hardwarecentral/reviews/193/1/>)
>
> The specifications of the P6BX-A+ are as follows:
>
>     * Chipset: Intel 440BX processor
>     * CPU: Intel Celeron, Pentium II & Pentium III
>     * Bios: Award
>     * RAM: 3 DIMM - Max 768MB
>     * Slot: 2 ISA, 5 PCI, 1 ISA/PCI shared and 1 AGP
>
>     I/O:
>
>     * One - EPP/ECP mode parallel port
>     * Two - 16550 high-speed serial I/O ports
>     * Supports 360K~2.88M Byte, 3 Mode FDDs or LS120
>     * Dual PCI IDE interfaces - PIO mode 4, DMA Mode 2, Ultra DMA 33
>     * PS/2 keyboard and PS/2 mouse connectors
>     * ATX Power Supply Connector
>     * Two USB connectors
>
> --
> small is beautiful
>
>