Re: Strange SATA info on boot


"Dr Teeth" <no.email.here.please@xxxxxxxxxx> wrote in message
news:u1k832tt80hjs2mdni24gabu2re0aisa7l@xxxxxxxxxx
I was just thinking how wonderful life was, when nospam@xxxxxxxxxx
(Paul) opened his gob and said:

The BIOS is normally set to Auto and in these modern times, should
use LBA. LBA, AFAIK, gives the largest addressability. CHS
has issues with the maximum number allowed for each of the fields.

Both (identical) drives sectors etc are identical in the BIOS

Try going into the BIOS, select the drive which is in CHS, and
set the BIOS to LBA explicitly and see what happens.

Access mode is either 'auto' or 'large'.

There are no issues with the drives, total available space is the
same.


Just a guess, but it seems to me that newer o/s do their own translation of
the drive geometry. The BIOS is not used other than for booting and perhaps
a suggestion of what the drive is for an o/s that uses BIOS translation. In
any case, my BIOS Auto on a WDC 40GB drive turns out to be the same geometry
as CHS not LBA as I expected. None of the translations (Large, CHS or LBA)
are a true reflection of the drive geometry. I think the number of sectors
per track is normally 17. On my system, Large and CHS report 255 sectors
while LBA reports 63 sectors per track.

I believe the translation schemes came from DOS. It had a problem of
1024x1024x1024 where there was a limit of 1024 (10 bit numbers) on any one
parameters (sectors per track, tracks per side and heads) so they came up
with Logical Block Addressing (LBA) to reduce any one physical parameter
below 1024 by increasing the other with logical translations. The number of
tracks was the problem as the sectors per track and number of heads are
usually less then twenty. You'll probably remember that the boot track had
to be below 1024 for some older o/s to boot.

I think Win95 also had a limit at 8GB because the number of sectors or
clusters reached a limit. FAT32 (bigger numbers) was the solution there.

That all disappears on SATA. The BIOS will still read the boot sectors and
boot the o/s but you don't get the opportunity to tweak the translation
scheme. They must have a standard though as I pulled my SATA off that slow
booting Promise SATA connector on my K8V and put in onto a VIA SATA
connector. It worked just fine without reloading the o/s so I suspect the
translation is still in the o/s on not in the driver or BIOS.

I finally screwed my drive by thinking Vista didn't need a SATA driver. I
tried to format a partition and it crashed with an error. My 80GB SATA drive
ended up with over 800BGB in one sector and unreal numbers in others. It
didn't mess with my working WinXP partition although the XP drive manager
doesn't report the drive any more. I decided not to mess with it any more
until I get my new system built.

Hope all that rambling helps somewhat.


.

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