I'm experiencing frequent "graying out" of my screen in memory-intensive programs like darktable so I'd like to test my RAM (installed 8GB). My Grub menu does not list Memtest as an option however the Ubuntu Software Center reports that Memtest is Installed. How do I run Memtest in this case?


output of grub directory:

-rwxr-xr-x 1 root root  9424 Jun 26 04:16 00_header
-rwxr-xr-x 1 root root  6058 May  8  2014 05_debian_theme
-rwxr-xr-x 1 root root 11608 May 15  2014 10_linux
-rwxr-xr-x 1 root root 10412 May 15  2014 20_linux_xen
-rwxr-xr-x 1 root root  1992 Mar 12  2014 20_memtest86+
-rwxr-xr-x 1 root root 11692 May 15  2014 30_os-prober
-rwxr-xr-x 1 root root  1416 May 15  2014 30_uefi-firmware
-rwxr-xr-x 1 root root   214 May 15  2014 40_custom
-rwxr-xr-x 1 root root   216 May 15  2014 41_custom
-rw-r--r-- 1 root root   483 May 15  2014 README
  • ...and why isn't memtest listed? Is it something you or someone else did? Can you add the output of ls -l /etc/grub.d/ to the question. Commented Oct 3, 2015 at 17:06
  • Have you looked in the "Advanced options for Ubuntu" section of Grub? Commented Oct 3, 2015 at 22:27
  • mikewhatever, the output is appended.
    – JD_Bugs
    Commented Oct 3, 2015 at 23:14
  • Grammargeek, not in Advanced options.
    – JD_Bugs
    Commented Oct 3, 2015 at 23:15
  • 2
    Possible duplicate of Where is the memtest option on the 12.04 64-bit live CD?
    – LiveWireBT
    Commented Jan 4, 2016 at 0:26

1 Answer 1


I also noticed that this option is missing, but never looked into it. Apparently the Memtest86+ image isn't compatible with UEFI and 20_memtest86+ exits very early when it's called on a UEFI machine:

# We need 16-bit boot, which isn't available on EFI.
if [ -d /sys/firmware/efi ]; then
  exit 0


  • A: Windows

    An alternative suggestion I found was to use Windows' tool for memory testing instead.

  • B: PassMark MemTest86

    There seems to be some confusion about Memtest86+ and the non-open source PassMark MemTest86, which supports UEFI since version 5.

    Arch have a script in their AUR to install PassMarks MemTest86. As an alternative to putting the files on a USB FAT partition you could do something similar by downloading the ISO for Linux/Mac then extract and rename the contents of EFI\BOOT on the ISO to EFI\MEMTEST86 on your ESP and add the following to your /etc/grub.d/40_custom:

    menuentry 'PassMark MemTest86 (x64)' {
        chainloader /efi/memtest86/bootx64.efi
    menuentry 'PassMark MemTest86 (ia32)' {
        chainloader /efi/memtest86/bootia32.efi

    Finally run sudo update-grub to update your GRUB configuration. (I included entries for both binaries, the old ia32 may not be supported with UEFI in Ubuntu, simply remove what you don't need.)

  • Here are the specific paths that worked for me: BOOTX64.EFI was in /boot/efi/EFI/memtest86/, and ESP partition was on /dev/sda3. The menuentry was then: menuentry 'PassMark MemTest86 (x64)' { set root=(hd0,gpt3) chainloader (${root})/EFI/memtest86/BOOTX64.EFI } Commented Jan 20, 2016 at 20:12

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