[ltp] PIIX vs UDMA? esp WRT vmware

[Andrew Steele]

Hi All,

I have a Thinkpad 600e which I have been dual booting between NT4SP5 and
Linux (2.2.15pre6).  Recently I installed vmware for linux on it and
proceeded to try and get vmware to work with my NT partitions as raw disks.

This proved to be non-trivial.  There is a problem which I don't know if I
saw reported here or just on some of the vmware newsgroups.  Basically when
using an NT rawdisk under vmware it will boot till just past asking for the
hardware configuration to use and then eventually BSOD with an
INACCESSABLE_BOOT_DEVICE error.

In the end I tracked it down to being the PIIX drivers which are part of the
Thinkpad IDE utilities disk.  Having this instead of having the disks
configured for UDMA (I'm using SP5) was the reason it was not able to find
it's boot device.

I suppose the other solution would be to rebuild my kernel to not support
UDMA, but most of the NT stuff I read seemed to suggest UDMA was "a good
thing".

So my Questions:

Could someone explain what exactly is the difference between UDMA and PIIX?

Why/Under what circumstances would you choose one over the other?

If UDMA is the better way to go (at least from an NT perspective), why do
IBM use PIIX?

What problems am I likely to find from using UDMA instead of IBMs preferred
PIIX?

Thanks
Andrew

--
Andrew Steele,
Senior Technologist
Newcastle Unix Services Group, BHP Information Technology
Selwyn Street, Port Waratah, 2304
PO Box 216 Hamilton, NSW 2303
Ph: +61 2 4940 2146, Fax: +61 2 4940 2165
mailto:fozzy@itntl.bhp.com.au
mailto:steele.andrew.aj@bhp.com.au
Remember, never ask a geek "why"; just nod your head and back away slowly...
"   Rob Malda -- slashdot.org


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