If you purchase one of those gargantuan new IDE drives but have an older BIOS, you may find that the BIOS does not see the drive. But BeOS only needs BIOS support for boot drives, not storage drives. You can still initialize and use BFS volumes on drives not seen by the BIOS just fine… or so it seems.
In truth, using a drive not seen by the BIOS means that no DMA level is sent back to the OS, so you won’t get full performance out of the drive — no DMA support at all. Worse, if you decide to get fancy one day and try to force DMA on by editing ~/config/settings/kernel/drivers/ata, you may very well hose your BFS partition, and be forced to re-initialize it and start over (I speak from experience).
If you can’t get your BIOS to recognize the drive, upgrade your motherboard’s BIOS and make sure the drive is detectable in the BIOS setup. You’ll get better performance and won’t risk data loss if you decide to make low-level changes via the ATA settings file (editing this file should never be taken lightly — make sure you know what you’re doing!)
Not having BIOS support for a drive is risky in any operating system, and BeOS is no exception. Be smart.