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Memory Test

UncleSchnitty

UncleSchnitty

macrumors 6502a
Original poster
Oct 26, 2007
851
14
What is the best way to test memory? Is the system report sufficient enough or should I run another program? I ask because I just ordered a new ram kit and I would like to test them when I first get them so I don't run into problems down the line. Any suggestions would be greatly appreciated.
 
UncleSchnitty said:
What is the best way to test memory? Is the system report sufficient enough or should I run another program? I ask because I just ordered a new ram kit and I would like to test them when I first get them so I don't run into problems down the line. Any suggestions would be greatly appreciated.
Click to expand...

Memtest is what you want.
 
UncleSchnitty said:
Is it normal when testing the memory it says "8013mb memory available and 8013mb allocated"?
I have 10gb installed, is the two missing because the program is run through osx?
Click to expand...

Yes... some memory is used by the OS that is running.

I have never tested it, but I suspect you could run the tool from single user mode to free up even more memory for testing.
 
Weaselboy said:
Memtest is what you want.
Click to expand...

...........
As another person posts, when I checked my RAM (not with Memtest but with TechTool) it only tested a certain amount of it, not the whole.
The complete series of nMP computer test results delivered by TechTool (which took a whole day!) were "all OK".
Do memory test programs have limits as to how much RAM they test? :confused:
In the About this Mac info the whole installed RAM is mentioned though.
Ed

P.S. I now see the answer given by Weaselboy. It answers also my question.
 
You can always pop in a Ubuntu 11.04 32-Bit disc (found that this one boots on Mac Pro 1,1) and select "Memory Test" from the purple boot menu.

Loads up MemTest+ x86 and fully tests the RAM.
 
Weaselboy said:
Yes... some memory is used by the OS that is running.

I have never tested it, but I suspect you could run the tool from single user mode to free up even more memory for testing.
Click to expand...
I was just testing it on the ram I currently have, I just wanted to make sure I understood what I was seeing before I ran it when I put the new ram in(I should have it early next week)
I assume the 2gb that's missing won't really make or break the test. Meaning if it passes then the ram should be good to go
 
Weaselboy said:
Yes, this is a limitation of all the memtest apps I have seen since some memory needs to be in use to run the OS, and cannot be tested while in use.
Click to expand...

Actually, MemTest has a very small kernel, and it relocates the kernel so that it can test 100% of the memory.

Relocation of the test is accomplished by using two copies of the test code that have been built to execute at different addresses (different origins). When the test is started, the code with an origin of 0x1000 is executed.

At the end of the testing phase the memory block from 0x1000 to 0xe400 is copied to 0x101000, the stack is set to 0x101000 and then we jump to address 0x108800 (the code with an origin of 0x108800). When the code is relocated only the first 640k of memory is tested.

When this test is complete then the code is moved back to 0x1000, the stack is set back to 0x1000 and then we jump to 0x1000 (the code with an origin of 0x1000).
Click to expand...
 
UncleSchnitty said:
I tried that and it just booted into OSX, they I tried Option-D and that booted into OSX as well.
Click to expand...

It seems you did a clean install and the AHT software is missing. From your signature, I assume it's a Mac Pro 3,1. In this case, you can download the AHT package form

http://download.info.apple.com/Apple_Hardware_Test/018-3273-A.dmg

1) Mount the dmg file, in the image, goto /System/Library/CoreServices/
2) Make the hidden file visible
3) Copy the ".diagnostics" folder to your bootdisk /System/Library/CoreServices/
4) Enable hidden file again

And now you should able to run the AHT by holding "D" during boot.
 
AidenShaw said:
Actually, MemTest has a very small kernel, and it relocates the kernel so that it can test 100% of the memory.
Click to expand...

Thanks for the correction. Is that reallocation trick something that was added in newer versions of memtest? I recall I researched this some time ago and this was not the case.
 
Weaselboy said:
Thanks for the correction. Is that reallocation trick something that was added in newer versions of memtest? I recall I researched this some time ago and this was not the case.
Click to expand...

It was already in Memtest86 2.8 Release (18/Oct/2001) ....

http://hup.hu/old/memtest86/index.html

I now see that the earlier link to MemTest was to an online Apple OSX tool.

The MemTest that I'm talking about is different - it's a standalone kernel that's booted from CD or thumb drive. See http://www.memtest.org/#downiso
 
Last edited:
Go with MemTest86

Weaselboy said:
I see... that explains it. The one I linked is a OS X native port of a Unix command line tool.
Click to expand...

The standalone one is the gold standard for memory testing on x64 platforms, I don't see any point in running an online test that only gets part of the memory.

When I bumped my new Dell T3610 E5-1650v2 system to 80 GiB, I let MemTest86+ run for two days before I even began to set the system up.
 
h9826790 said:
It seems you did a clean install and the AHT software is missing. From your signature, I assume it's a Mac Pro 3,1. In this case, you can download the AHT package form

http://download.info.apple.com/Apple_Hardware_Test/018-3273-A.dmg

1) Mount the dmg file, in the image, goto /System/Library/CoreServices/
2) Make the hidden file visible
3) Copy the ".diagnostics" folder to your bootdisk /System/Library/CoreServices/
4) Enable hidden file again

And now you should able to run the AHT by holding "D" during boot.
Click to expand...
It was a clean install. I did what you said and its still not working, strange.
 
h9826790 said:
Try to repair permission

If still doesn't, try another version

http://download.info.apple.com/Apple_Hardware_Test/022-4020-A.dmg

This is also for Mac Pro 3,1
Click to expand...
I tried that one as well still a no go. Its weird that these aren't working. How are you finding these? when I go to http://download.info.apple.com/Apple_Hardware_Test/ it just gives me dl options for the PPC. How are you finding the ones for intel, specifically for 3,1?

I guess it really doesn't matter, my tracking says my ram will be here tomorrow so if i run any of the in OS memtests I guess that will give me a pretty good indication if the ram is ok or not. Its just weird these aren't working
 
UncleSchnitty said:
I tried that one as well still a no go. Its weird that these aren't working.
Click to expand...

That's weird. After my 4,1 did a clean install. I simply go to that link and download the AHT to recovery this function, it works. Of course, I change the model number to get the dmg for my 4,1 instead of 3,1.

As you can see, the link will take you to the Apple server. Not any unreliable source. And you are right, the file is alway there, but Apple only provide the public link for the very old computer. You need to know the exact file name to download the correct dmg file.

Anyway, for the memory itself, run Memtest should be good enough already.
 
Last edited:
h9826790 said:
That's weird. After my 4,1 did a clean install. I simply go to that link and download the AHT to recovery this function, it works. Of course, I change the model number to get the dmg for my 4,1 instead of 3,1.

As you can see, the link will take you to the Apple server. Not any unreliable source. And you are right, the file is alway there, but Apple only provide the public link for the very old computer. You need to know the exact file name to download the relative dog file.

Anyway, for the memory itself, run Memtest should be good enough already.
Click to expand...
I dont know, I found another link that had a third 3,1 but that didn't work either. Ill just do a memtest in OSX when they get here and hopefully that will be a good enough indicator that I don't have a bad stick in the batch
 
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