Hello.

I'm wondering if other people with the same mobo have come across this and have a solution.

The motherboard has the latest BIOS 1024.001. The USB disks are connected to an external powered hub. The results are the same if I connect them directly to the mobo.

If I connect a big disk (FreeAgent 750GB, My Book 1TB) the system refuses to complete the BIOS post. It hangs trying to identify the USB disk.
It can recognise a LaCie 500GB but hangs again if I try to connect another similar LaCie.

If I connect the disks after the post, everything is working fine.

Is that a BIOS limitation of some sort? (There is a reference on the BIOS about treating USB disks of around 500GB as floppy disks or something like that -- I'm using the defaults).

Thanks in advance.

Sometimes the problem has to do with the low-level USB interface controller chips used. The chips that manage protocol between the disk and the USB port on your computer, for example. It's not that uncommon, even when you're dealing with USB2.0 device to USB2.0 port connections.

Having it work on a USB hub but not directly attached to your computer is an indication this may be your problem. This is even more of a problem when dealing with a mix of USB2.0 and USB1.x ports/devices. Even though they are supposed to be downward compatible, some USB2.0 devices/ports devices don't play well with USB1.x devices/ports.

I'm surprised it's causing such a major boot-time problem, but it may simply be a matter of multiple retries and waiting for the time-outs over and over again. Eventually it might either recognize or void the connection, but could take a while to do so.


edit to add-the reason it might occur when connected at boot but not if connected after the system has come up, is that device initialization sequencing probably changes the transaction timings, and that could be enough to change how the protocol chips handle the transactions.
(this should be the last edit)

Thanks for the reply.

All the USB devices I have are v2.0. I could remove all USB devices but the moment I plug in just one of the big disks, the boot up freezes. It looks more like a limitation of the BIOS rather than the controller.
I also thought it might be a timing problem but I've left the system, had lunch, and it was still stuck there when I was done.
Unfortunately Asus is not good at updating BIOSes once their new models hit the market.

Terry Kanenas said:
Just to be clear...even if all the devices are 2.0, there can still be low-level controller chip/chip-set issues. For example, a USB2.0 controller chip made by Cypress can have timing problems with a USB2.0 controller chip made by Via. This is chip-level...not adapter card or Hub level.

As you suspect, it could be BIOS related, but I suspect you're more likely to be looking at a USB chipset or related issue (which is probably complicated by a BIOS/sequencing-timing issue) Note: in some cases, you can find a "patch" that will correct a USB controller problem at the firmware or driver level, but these sometimes simply change timing, and can reduce performance. The underlying problem cause remains, but the symptoms are masked. Ideally in these situations, you want to eliminate the cause of the problem.


If you can open the disk drive enclosure, I'd connect the drive to another USB controller or adapter and test after temporarily eliminating the USB controller that is currently on your disk drive. A very easy adapter to use for debugging is one of the combined USB2IDE+SATA adapters...usually US$10-$30.
http://www.geeks.com/details.asp?InvtId=2020
http://www.tigerdirect.com/applications/SearchTools/item-detai...;CatId=470
http://www.tigerdirect.com/applications/SearchTools/item-detai...p;CatId=81



Here are some links for more USB problems information.

http://www.usb.org/kcompliance/view
http://www.usbman.com/USB_Guides.htm
http://www.lvr.com/usbchips.htm



edit to add: comment on potential performance impact of "patches" and "fixes"

Thank you.
I'll go through the links you've posted but I suspect I'm stuck.

I don't see any obvious way to open the enclosures of these drives and I don't want to risk it either. They are brand-new and I would rather not mess up the warranty.

It looks like I have to live with it until I replace the mobo (should have done it some time ago).

Much appreciated for your help.

Had the same problem myself.
Saw your forum and made me think.....

Found a very simple solution that worked for me.

DISABLE LEGACY USB SUPPORT in the BIOS.

My attached USB WD 750Gb h'disk doesn't cause a freeze a bootup now and goes into Windows without error.

Hope this helps

Hi all

Just bought my FreeAgent 750GB, the systealso refuses to complete the BIOS post. It hangs trying to identify the USB disk.. The following are the system detais wirh XP Home SP2.

Any thoughts to get the FreeAgent 750GB, working without haveint keep disconnecting and pluging in just before windows starts

Product name Intel(R) Desktop Board D865PERL based system
Board model Genuine Intel(R) D865PERL system board
OS version Windows* XP version 5.1 Service Pack 2 build 2600
OS memory 2,097,152 KB RAM

Physical memory 2,560 MB RAM
Memory speed DDR400
Memory type DDR, Synchronous
Form factor DIMM
BIOS date 01/22/2004
BIOS size 512 KB
BIOS version P13 (RL86510A.86A.0071.P13.0401221036)