1TB HD showing 31MB/32MB/33MB capacity

Franc Zabkar · Oct 11, 2009

Here is an interesting post describing a BIOS bug. It causes 1TB
drives to be incorrectly downsized after the BIOS grabs some 2000
sectors at the top end and hides them in a HPA for the purpose of
"auto recovering a damaged BIOS to its original state".

http://forums.seagate.com/stx/board...&view=by_date_ascending&message.id=1706#M1706

Here is one instance of the problem:

http://forums.seagate.com/stx/board/message?board.id=ata_drives&message.id=15702#M15702

Here is a Gigabyte blurb:

http://www.gigabyte.com.tw/Support/Motherboard/TechGuide_List.aspx?NewTechID=84

"Xpress Bios Rescue – Auto recovers damaged BIOS to its original
state! BIOS Image is stored in your HDD hidden area automatically when
system boots up."

This article explains the HPA:

http://en.wikipedia.org/wiki/Host_protected_area

- Franc Zabkar

Franc Zabkar · Oct 13, 2009

I have a board that supposedly does this. I did not dare
to try it. Seems that was a good idea...

Here's another case where a 1.5TB HD was truncated to 500GB:

http://forums.seagate.com/stx/board/message?board.id=ata_drives&message.id=15736

It appears that the buggy BIOS wraps the LBA count after 31 bits.

- Franc Zabkar