This is something I've been upset about for the last month.
I have an Iomega DHD250-U external USB2.0 Hard Drive and a Vantec NexStar
external 3.5" HD enclosure with USB2.0 interface (which uses the Ali M5621),
and a Shikatronics Travelling Disk, USB1.1 Key Disk.
I have asked the same question and not received any response from several
stores and ng.
So far:
Asus A7N8X Deluxe 2.0 UAYZ nForce2 400 (1007)
- no combination of BIOS setting, or jumpered +5VSB for the USB ports will
enable booting from any of my USB devices. Is it an IRQ issue? The POST
displays the USB Key as detected, but fails to even try to boot from it.
POST fails to see USB HDDs at all.
- booting with a WME FD complete with the Panasonic 'magical' 2.15 USB
driver along with the DI1000 ASPI driver, all three onboard controllers are
recognized. My USB mouse, the Key Disk and the NexStar are recognized, but
only the Key Disk is assigned a drive letter by the DI1000 ASPI, and only
after the +5VSB USB jumper is set.
- booting with the IOMEGA USB/FireWire DOS boot diskette; I can now access
the Iomega drive. The same FD fails to detect the Vantec. The Iomega
OHCI/UHCI (1.1) drivers see nothing at all. The Iomega EHCI (2.0) driver
IDs the Vantec drive but then freezes and goes nowhere.
Asus P4P800VM
- natively can boot to the USB Key Disk and the Iomega USB HDD without
external drivers or a FD.
Asus P4BGLMX533
- booting with the IOMEGA USB/FireWire DOS boot diskette; I can access the
Iomega drive.
- it was a busy day, so I can't recall clearly if the Panasonic/DI1000 also
worked
- the BIOS has the same useless settings as the A7N8X Deluxe 2.0 and the
same results for native support
Asus K8V? (not certain on this model name)
- no native support despite what the BIOS said
- the Panasonic drivers could see the key disk, and I believe the NexStar.
Not entirely comprehensive testing, but so far, the Iomega drive appears to
be the best bet for USB HDD. The P4P800VM is the ONLY mobo that I know of so
far that has native USB booting capabilities.
I've asked for recommendations of other empirically witnessed USB booting
motherboards, but have received no replies yet.
