BIOS update, EIDE card, or overlay software? (FAQ Hard disk recognition)
#42825 by Denniss
Sun Dec 31, 2006 6:42 pm
First the bad news: We can't patch/update Bios for native support of HDD over 128/137GB.

But the good news: If your Bios won't provide 48 Bit LBA support for drives above 128/137GB then you have additional options:

W2K SP4, WinXP SP1, Linux
You won't need native Bios support if you have Windows2000 SP4, Windows XP SP1 or Linux with a somewhat recent kernel (2.4.18 upwards). Install your OS into a partition within Bios limits and allocate space above Bios limits within the OS.

Win9x
Win9x (Win95 OSR2.x, Win98, Win98SE, WinMe) needs native Bios support to be able to use drives above 128/137 GB but there are several other requirements:
It's a lot more tricky with Win9x as these OS do not have support for drives larger than 128/137GB because their standard IDE driver lacks support for 48Bit LBA-adressing. Some chipset and Controller manufacturers may have released drivers supporting these big HDD but they usually need a Bios fully supporting 48BitLBA to operate drives above 128/137GB.

If your motherboard chipset manufacturer does not provide drivers for big HDD then you might try patched Win9x IDE drivers matching your currently installed OS and driver version (these are based on corresponding Win9x standard drivers). You may need updated Fdisk, Scandisk and Defrag programs from WindowsMe to not screw up your file system.

Instruction how to install/use these drivers, download and lots of more Information is to be found here: http://www.msfn.org/board/?showtopic=78592
Please carefully read the instructions and requirements how to use these files!! The use of these patched drivers is on your own risk so backup important data first !!!

ALi 15x3
The IDE controller integrated into ALi 15x3 rev. C4 and below does not support LBA48 when using DMA. Only PIO modes are available when using LBA48 which slows down transfers noticeably. This is a hardware issue with the IDE controller and can not be fixed. ALi 154x3 revisions above C4 support LBA48 and DMA.

Another good link with lots of Info is here: http://www.48bitlba.com/