AN7, Hard disk Boot Priority & USB Hard disk redetection

[A User]

Okay, first post. I have an Abit An7 motherboard, and am using bios an7_19 with the latest SATA 4.2.83 bios and drivers (kindly provided by AdvModDev at http://www.nforcershq.com/forum/new-sil3112-sata-bios-from-silicon-image-vt69371.html?highlight=an7+bios )

I recently changed from a 40Gb PATA HDD to a 160Gb SATA HDD (Seagate DiamondMax 20 STM3160211AS). I have Windows XP installed on the SATA drive. I also have an external USB 2.0 250Gb hard drive (Seagate ST3250823A) which I use purely for file storage.

The problem is minor but irritating. Every time the BIOS detects the USB HDD, it puts it at the top of the list in the "Hard disk Boot Priority" i.e.:

1. USB-HDD0: ST3250823A
2. Bootable Add-in Cards

This causes the system to display the message DISK BOOT FAILURE INSERT SYSTEM DISK AND PRESS ENTER, because the USB HDD is not bootable, and so I have to reboot and go into the BIOS and change the "Hard disk boot priority", putting the bootable add-in card (SATA) at the top of the list **or** turn off the USB HDD (cradle switch round the back) and then reboot - this works because the only HDD populated in the list will be the bootable add-in card (which is set to SATA).

Here is an example scenerio where this becomes a problem:

1. I turn on my PC, it boots into Windows XP from the SATA drive. At this point the BIOS doesn't know about the USB HDD, as maybe I haven't had the USB HDD switched on for a few days.
2. Once in Windows, I turn on the USB HDD by flicking the cradle switch for the power. A drive letter is assigned to it in Windows.
3. I install a new piece of software which asks me to reboot.
4. I reboot the PC with the USB HDD still switched on, and the DISK BOOT FAILURE message is displayed (because the BIOS previously detected the USB HDD and put it at the top of the "HDD boot priority" list.)

It seems strange that the BIOS does not detect that the USB HDD is non-bootable and then try to boot from the next available drive i.e. the SATA drive. Instead it just sits at the above error message.

I've tried going into Integrated Peripherals-> Onchip PCI device and setting "USB KB, Storage support" to OS (rather than set to BIOS). I would expect the effect of this to be that the BIOS does not detect the USB HDD, but it seems this is not the case because it still populates the "Hard disk boot priority" list with the USB HDD when it redetects it. So my second guess is that this option only applies to USB flash disks (and USB keyboards of course).

Anyone know how I can get round this problem? Obviously the workarounds mentioned above are not ideal.

As an aside, I also noticed that in order for the SATA disk to work at all, not only does the "Serial ATA Controller" option have to be enabled in the BIOS (as expected), but also the "SATA RAID ROM" option has to be enabled. Else, I get the same message again DISK BOOT FAILURE INSERT SYSTEM DISK AND PRESS ENTER. This seems odd if you're not intending to use the RAID functionality, and just have a single SATA disk. Has anyone else noticed this?

[Oldphart]

As far as the USB thing, I believe you have to disable "boot from other device". But The raid boot rom has to be enabled in order for it to boot from the SATA drive. That is because it uses a Silicon Image 3112 sata raid chipset on the board that is recognized as a SCSI device, as if it was a add-on card. This is normal for any board that does not use Native NV raid that is built into the southbridge.

[A User]

Thanks for your reply Oldphart. I already had "boot from other device" disabled.

It seems the problem I have encountered is a quirk of the way the Bootable Add-in card, in the "Hard disk boot priority" list, does not hold onto its set priority when USB HDDs are detected.

The AN7 BIOS has lots of settings which are great for tweaking, but I do miss having the option of a boot sprite - a small menu which displays after posting, allowing you to choose which HDD to boot from.

What you say about the SATA RAID ROM makes perfect sense - it's nice to understand why these things work like they do.