Conflicting memory tests

TV2 · 02 Mar 2019

Testing a new rig with 32GB (2x16) of DDR4, 2333MHz ram (Patriot Viper Elite PVE432G266C6KGY) on an Asus Prime Z390-A motherboard.
BTW- Patriot 2666 RAM is not on the QVL for this board (none). Thought I'd chance it, Patriot makes good RAM, usually.

I ran Memtest86 (by Passmark) and it threw out errors. 9 on one 4-pass test, 15 on another.
I did due diligence: ClearRTC, CPU Parameter Recall - still errors.
I switched the modules from slots A2/B2 to slots A1/B1 and it threw up 51 errors on the first pass.

So bad RAM, right? I set up a return RMA, and bought some Corsair RAM that is on the QVL. Live and learn.

So while I'm waiting for the new RAM I decided to try another RAM test. Pulled out my old Memtest86+, v5.01 and ran that overnight. 7 passes, no errors.

So what am I to believe here? The Passmark Memtest86 is a newer program, the Memtest86+ is almost 7 years old and has not been updated.
My decision is made, but now I'm wondering....

zbook · 02 Mar 2019

Memtest86+ version 5.01 and Memtest86 version 8.1 have different algorithms and different update dates.

DDR4 RAM was released in 2014:
DDR4 SDRAM - Wikipedia

Memtest86+ version 5.01 as last updated: LAST UPDATE : 27/09/2013

It's best to use the Memtest86 version 8.1 as it has been updated to test DDR4 RAM.

Testing methods are also important.
For example, every test can have true positives, true negatives, false positives, false negatives, and accuracy.

For any memory test the more the passes the better the testing conditions.
The minimum passes used for Memtest86+ version 5.01 that we regularly use for testing is eight.
However there have been tests where it has taken passes into the twenties to display errors.
So all of the tests up to the twenties would have produced no errors, or false negatives.

The memtest86 version 8.0 was able to make eight passes as a free version.
In January 2019 the software was updated to 8.1 and the free version can now only perform four passes.
Currently two tests of four passes each is being used. This is discontinuous testing.
In order to perform continuous eight pass testing the only option is the paid version.

TV2 · 02 Mar 2019

Thank you. That explains a lot. Obviously I trusted the memtest86 results. Too many errors too soon. Pretty clear.
I will put Memtest86+ away. It had a good run.

Let's hope the Corsair Ram fairs better!

TV2 · 03 Mar 2019

Corsair RAM came last night.
Passed the first 4 passes in Memtest86 with no errors. Got second 4 going now.
Seems the Patriot RAM was defective or incompatible.