How to use Memtest86 on a Mac using a CD

[Beth Leonard]

After spending a long time figuring out the following information, I thought I'd share. Note: this has only been tested on a 2009 iMac running Mac OS 10.6.8 (Snow Leopard).

1. Download the the Linux "Image for creating a Bootable CD"
2. Open a terminal window. Click from finder:
Applications->Utilities->Terminal
3. Navigate to the downloaded image. Type:
cd Downloads
4. Unzip the file. Type:
gunzip memtest86-4.1.0-iso.gz
Note: if the version name changes between when I write this and when you read these instructions, you can likely type "gunzip mem[tab]" and file completion will complete the rest of the name correctly for you.
5. Rename the file to have a .iso file extension so that Disk Utility will recognize it. Type:
mv memtest86-4.1.0-iso memtest86-4.1.0.iso
6. Open Disk Utility. Click from finder:
Applications->Utilities->Disk Utility
7. Open the disk image. Click from disk utility:
File->Open Disk Image...
Chose Downloads->memtest86-4.1.0.iso
8. Now in the list on the left of Disk Utility below the horizontal line, you should see an icon with "memtest86-4.1.0.iso" on it and "CDROM" underneath. Click the top line that says, memtest86-4.1.0.iso.
9. In the icons at the top of Disk Utility, click the 3rd one from the left that says, "Burn" Insert a burnable CD in the drive and burn the CD.
10. Power down your computer.
11. Boot the computer again with this CD in the drive, and hold down on the 'c' key while the computer is booting to tell it to boot from CD.
12. After about 60 seconds the computer boots from this CD and starts running memtest automatically.

Please post any updates to this procedure.

--Beth

[David (PassMark)]

Thanks for that.

It is also possible to use a USB drive prepared on a Windows or Linux machine (or the pre-made drives we sell) to test a Mac.

Note that this won't work on the older PowerPC Mac. It was January 2006 when Apple started switching from PowerPC CPUs to Intel x86 CPUs. So machines earlier than 2006 definitely won't work.

To get a Mac to boot from USB you need to hold down the ALT / Option key on the Mac keyboard while powering on the machine.

[Helipil0t]

Thanks for that.

It is also possible to use a USB drive prepared on a Windows or Linux machine (or the pre-made drives we sell) to test a Mac.

Note that this won't work on the older PowerPC Mac. It was January 2006 when Apple started switching from PowerPC CPUs to Intel x86 CPUs. So machines earlier than 2006 definitely won't work.

To get a Mac to boot from USB you need to hold down the ALT / Option key on the Mac keyboard while powering on the machine.

I have created a bootable USB thumbdrive with memtest86 and managed to boot from it on my MacBook Pro (late 2009) model flawlessly using rEFit as the boot manager. However I cannot get it to boot on a 2012 27inch iMac. No matter what disk image I use to create the boot drive, I keep getting a "No boot media detected" error message when selecting the drive via rEFit. How can the iMac be any different than my MacBook? Is there something that I'm missing here?

[David (PassMark)]

We aren't aware of any issue.

This article from Apple has a few suggestions & notes.
http://support.apple.com/kb/ht1948

Including trying a different USB port, not using a hub and not using it is boot camp.

You shouldn't need to use rEFit.

[pdimh]

Hi,

I tried the cdrom method and didnt worked on my macbook pro (mountain lion). It tries to boot, but the screen gets dark (all black).

I used the same cdrom on a pc and worked fine. Tried a usbstick and it gives the same error.

am i doing something wrong?

Thanks in advance.

[David (PassMark)]

What version of MemTest86 are you using?
What year was the Macbook from?

We boot V5 on a 2013 era Macbook without any problem. You hold down the Option key, pick the USB drive and it boots.

[pdimh]

What version of MemTest86 are you using?
What year was the Macbook from?

We boot V5 on a 2013 era Macbook without any problem. You hold down the Option key, pick the USB drive and it boots.

I tried V5 and it worked perfectly! Thanks.
I was trying 4.33 on a macbook pro, mid 2012.

My new pair of ram will arrive tomorrow and i would like to test them.

Thank you very much!