ASUS Sabertooth X79 + 16GB Flash USB > Unable to boot in UEFI

[saladspoons]

I'm unable to get MemTest86 v.5 USB Flash boot to work.

I've built the USB Flash boot drive using the v.5 USB Boot creator on this site (and have also tried RUFUS (http://rufus.akeo.ie/) to create a GPT+FAT32 flash boot drive using the memtest86 .iso file).
http://www.memtest86.com/download.htm

• Image for creating boot-able CD
• Image for creating boot-able USB Drive

Both methods have the same results - I go into the UEFI bios, boot menu, see the USB drive listed multiple times (as UEFI and Legacy modes). When I boot using UEFI, nothing happens, it just kicks me back into the BIOS. When I boot to Legacy mode, it launches MemTest86 v. 4.3 from the USB drive just fine. I get the same result even if I turn legacy mode off and try to force UEFI only USB boot device support ...

Does anyone have any hints for how to force the UEFI boot to work?

ASUS Sabertooth X79
64 GB Corsair Dominator Platinum RAM
BIOS set in either Legacy or UEFI only USB modes
16GB External USB Flash drive

[David (PassMark)]

There should be no need to use RUFUS anymore.

The ASUS Sabertooth X79 is a couple of years old now. Which means it would have been one of the early generation UEFI boards. Can you try updating the BIOS, maybe ASUS have fixed something.

[saladspoons]

Problem solved .... I found the issue was with the "Secure Boot" feature of the UEFI bios - I had to select either "boot into Windows" or "Other OS", and choose "Other OS" so that it could boot into Linux from the USB drive.

Seems everything is working fine after all - very nice the way it can boot in either UEFI OR Legacy mode too ... well done guys!!

Thanks!

[David (PassMark)]

We aren't using Linux in V5 of MemTest86. But the issue is the same. Secure boot needs to be disabled.

Glad you sorted out the problem.