System with DDR4 memory fails MemTest86 V5.01

[jp59]

I was using MemTest86 v. 5.01 to test a computer with four banks, two channels, of DDR4 ram installed. Running all tests (1-11), with all eight cores in parallel, could not be executed ten (10) consecutive times without an error. Every error encountered was always during Test #7 [Block move]; and always CPU 1 or 2 was indicated. Reducing the number of DIMMs and/or moving to different a slot would not allow for a consistent error free series of 10 consecutive passes (usually the first errors would be encountered during Pass 3-5). I eventually scaled down to just running Test #7 to help speed up the troubleshooting, but never could narrow down to a single slot/DIMM that would run error free.

Next I switched to using MemTest86 V6.3.0, and put the system into UEFI mode. I did a quick test of running Test #7 eleven (11) consecutive times against a single DIMM/slot that had failed earlier; this was successful, and 100% error free.

Now I'm currently running all tests (1-13), with all eight cores in parallel, for eleven (11) times. It's actively running Test 9 [Modulo 20, ones & zeros] in Pass 3 without encountering any errors so far.

My question to others who have MemTest86 experience, if all eleven passes of MemTest86 V6.0.3 are successful, should I still be concerned about the errors that were reported during the testing with MemTest86 V5.01?

Thanks in advance,

-jp

[David (PassMark)]

I think you are confusing MemTest86 with MemTest86+.
MemTest86+ isn't our software.

There is a bug in MemTest86+ V5.01. It produces false positives on Test #7.
There are some details here,
http://forum.canardpc.com/threads/10...kylake-i7-DDR4
and here
http://forum.canardpc.com/threads/97...ell-Server-bug

It has been over a year since the bug was reported, but the author of Memtest86+ hasn't provided a fix as yet.

So we'd suggest using MemTest86 V6 or V7 instead. Which we have tested with Skylake CPUs and DDR4.

[jp59]

David,

Thank you for replying, and for the URLs. You are correct, I was using MemTest86+ to test with. This system has a Skylake CPU installed. I ran eleven consecutive full parallel test runs using V6.3.0 PassMark MemTest86 without an error. Another plus, it correctly reports the Make/Model of the memory installed.

-jeff