Memtest OS X - Essential Tool for Testing Your RAM

[ravenvii]

Memtest is an essential tool for testing your RAM. If you are experiencing kernel panics or freezes, your RAM should be one of your first suspects. Or if you've just upgraded your Mac's RAM, and want to ensure that it is all good before you sell the old RAM. Or you merely want to make sure your RAM is good, so that in the future you can eliminate it as the source of the problem.

Whatever your situation is, if you need to test your RAM, Memtest OS X is the best tool for the job for your Mac. Yes, there's Memtest86+ - I always use that for all the PCs I own. However, there's a bug in Memtest86+ where it could give false positives on EFI machines (which all Intel Macs are).

Memtest, by the way, is open source. So why, then, do you have to pay to download it? You have to pay to download both the binary and the source. I believe this violates the GPL, which Memtest OS X, and Memtest before it, are released under.

So I'm attaching Memtest right here in this thread. Now you can download it for free, without having to pay. Unfortunately, I don't have the source .

To start the program, simply start it in the Terminal. It is suggested, however, that you use it in Single-User Mode for best results.

To boot into Single-User Mode, hold command-S on boot.

Then type those commands:

/sbin/fsck -fy

/sbin/mount -uw /

The first command is a quick checkup of your HD. Not strictly necessary, but it only takes a few seconds, and is generally a good idea.

Once the HD is mounted, cd (change directory) to where the memtest program is located. For example, if you put memtest in your Applications folder, the path would be:

cd /Applications

Or if you put it in the Utilities folder, it would be

cd /Applications/Utilities

And so on. You get the idea.

Then you can run memtest with a simple "./memtest" command. However, there's stuff you can customize. The first is how much memory you want to test. I'd say all, so just put "all" after "./memtest". Then comes how many times you want to run the test. 3 to 5 are good numbers, so just put that number after "all". Then you can decide whether you want the results logged or not with a -L. There's more, but those are the basics, and all you need to know.

So a simple 3-round memtest test of all available memory would be:

./memtest all 3

That's it.

[Shownarou]

This sure looks an awful lot like an advertisement..

[ikermalli]

He's been here almost 5 years and has 4000+ posts and he is giving out the binary for it free. Doesn't seem like an advertisement.

Thanks for this, does this work with Snow Leopard?

[ravenvii]

Originally Posted by ikermalli

He's been here almost 5 years and has 4000+ posts and he is giving out the binary for it free. Doesn't seem like an advertisement.

Thanks for this, does this work with Snow Leopard?

Yep it does work perfectly under Snow Leopard. 64-bit mode and all.

[Shownarou]

Originally Posted by ikermalli

He's been here almost 5 years and has 4000+ posts and he is giving out the binary for it free. Doesn't seem like an advertisement.

Thanks for this, does this work with Snow Leopard?

Oh, okay I get it. Sorry about that OP. Thanks by the way!

[appleguru1]

Thanks for this!

This is the latest Memtest version 4.22 (64-bit) :-)

Though the developer's $1.39 fee is hardly unfair, and AFAICT is permitted per the GPL v2 that it is licensed under. I'm fairly certain he has to make the source available though..

[rpaloalto]

Thanks

[dukebound85]

i use rember
http://www.kelleycomputing.net/rember/

its a gui version of memtest and is free

[Ibjr]

Originally Posted by Shownarou

This sure looks an awful lot like an advertisement..

You're just too cool for school.

[Shownarou]

Originally Posted by Ibjr

You're just too cool for school.

Did you even read the rest of the thread?

[krunk]

Memtest, by the way, is open source. So why, then, do you have to pay to download it? You have to pay to download both the binary and the source. I believe this violates the GPL, which Memtest OS X, and Memtest before it, are released under.

Have you asked for the source from the author? If I understand the GPL correctly, you are not required to host the source. But you are required to provide the source if asked.

-james

[ravenvii]

Originally Posted by krunk

Have you asked for the source from the author? If I understand the GPL correctly, you are not required to host the source. But you are required to provide the source if asked.

-james

You are required to pay the money to download memtest to get the source. Which is why I went and put memtest up here for free. If the developer puts up the source without the download fee, then I would remove the download here, since the developer is acting within the GPL license. Since he is not, I decided to take things into my own hands

And re: Rember, memtest is better because you can use it in single-user mode, and hence memtest will be able to test more of your memory than Rember can (it couldn't test memory that's tied up by OS X, UI elements and programs running in the background).