memtest86 results - 2010 Macbook Pro

[ouestjojo]

Hello folks,

I bought a 2010 Macbook Pro used off Kijiji. The seller said it needed a new Logic board, but it was really cheap, so I figured I would take a chance. Over 2 or 3 days, it only Kernel panicked on me 1 time, and I was using it all the time. i even managed to install windows on it through bootcamp with no problems.

Ran memtest86 and got the following results:



I was surprised because after 13 hours it hadn't yet completed, but I ended the test anyways, because I didn't see much purpose in going further. doubt both Ram sticks are dead, so it may in fact be the logic board.

I guess the thing that is throwing me is that the results are SOOO bad, and the confidence value Soo low, that I wonder if there might not be something else going on.

Further, like I said generally I run it without any real hiccups...

Any insight would be appreciated.

Thanks a lot,

JG

[ouestjojo]

Also!

I should note that Apple Hardware test gives me no errors...

Thanks,

[keith]

Given that the high and low error addresses specify a specific range in high memory, it may be that the BIOS has not properly marked that particular memory range as being reserved/unusable. So MemTest86 may have been testing a non-RAM device (device memory, MMIO, etc..) mapped to that range.

Address range in question was 000ae000000 - 000affffffc (2784 - 2815.9 MB)

You can try testing 1 stick at a time or replacing it with known good RAM and see if it makes a difference in the results.

[ouestjojo]

Given that the high and low error addresses specify a specific range in high memory, it may be that the BIOS has not properly marked that particular memory range as being reserved/unusable. So MemTest86 may have been testing a non-RAM device (device memory, MMIO, etc..) mapped to that range.

You can try testing 1 stick at a time or replacing it with known good RAM and see if it makes a difference in the results.

Thanks a lot for your reply!!

I figured something squirrely was going on!!

Thanks!

[David (PassMark)]

After some searching it seems this problem has been reported before, back in 2010 on Macbooks.

The conclusion at the time was,

Seems clear that this memory area isn't writable (all bytes remain to 0xFF when read) but nevertheless the area is marked as writable in the e820 memory map (in BIOS). Thanks to a bugged Apple EFI BIOS. The same issue appeared in first EFI-based Macbook some years ago. Apple finally corrected that, but after several months.

So can you check if there is newer firmware available for this Mac?
Also there was a suggestion that this area of memory might have something to do with the USB functionality. So can this be disabled in BIOS as a test?

There is even a Youtube video showing similar behavior
https://www.youtube.com/watch?v=uYQVZHc449Q