MEMTEST86 and (maybe) weird results depending on BIOS configuration.

[David19800]

Hi. I built a new system around a Gigabyte X99 Ultra Gaming with a 5820K CPU and 64GB 2400 C14 Memory Kit that is in the QVL (supported/tested list) of the motherboard.

I tested the system with Memtest86 v7.2 Free and got these (weird) results:
(read carefully to understand)

CPU clock / Memory Clock / Errors
3300 / 2400 (1,20V XMP1) / more than 100 (stopped in test #3)
3300 / 2133 (1.20V) / 24 (8 errors in #4 16 errors #5, stopped afterwards)
3300 / 2666 (1,35V XMP2) / more than 100 (stopped in test #1)
4000 / 2133 / 0 errors in all 13 tests (1 pass after 3h 15m)

So...

• 
  ■ Without overclocking my CPU and only using the XMP1 (the official 2400Mhz memory speed) I got many errors and I stopped the test after a few minutes.
  ■ I lowered the memory to 2133 (below the official 2400) and seemed OK but Test 4 (out of 13) had some errors and even more in Test 5, and I stopped the test after that. So better but still some errors.
  ■ Still without overclocking my CPU and I used XMP2 (2666) but lots of errors like XMP1.
  ■ I overclocked the CPU to 4000 (from 3300 by using the "Performance" setting of the Easy mode of BIOS) and the standard 2133 in the memory (No XMP) and after 3 hours ALL the 13 tests were FREE of Errors.

Does this make any sense?

(I might have a vague explanation but I need your thoughts and expertise)
(Also I would like to test the overclocked CPU with XMP1 but to tell you the truth I don't want to fiddle with it and spoil it)

 

[David19800]

Hi. I built a new system around a Gigabyte X99 Ultra Gaming with a 5820K CPU and 64GB 2400 C14 Memory Kit that is in the QVL (supported/tested list) of the motherboard.

I tested the system with Memtest86 v7.2 Free and got these (weird) results:
(read carefully to understand)

CPU clock / Memory Clock / Errors
3300 / 2400 (1,20V XMP1) / more than 100 (stopped in test #3)
3300 / 2133 (1.20V) / 24 (8 errors in #4 16 errors #5, stopped afterwards)
3300 / 2666 (1,35V XMP2) / more than 100 (stopped in test #1)
4000 / 2133 / 0 errors in all 13 tests (1 pass after 3h 15m)

So...

• 
  ■ Without overclocking my CPU and only using the XMP1 (the official 2400Mhz memory speed) I got many errors and I stopped the test after a few minutes.
  ■ I lowered the memory to 2133 (below the official 2400) and seemed OK but Test 4 (out of 13) had some errors and even more in Test 5, and I stopped the test after that. So better but still some errors.
  ■ Still without overclocking my CPU and I used XMP2 (2666) but lots of errors like XMP1.
  ■ I overclocked the CPU to 4000 (from 3300 by using the "Performance" setting of the Easy mode of BIOS) and the standard 2133 in the memory (No XMP) and after 3 hours ALL the 13 tests were FREE of Errors.

Does this make any sense?

(I might have a vague explanation but I need your thoughts and expertise)
(Also I would like to test the overclocked CPU with XMP1 but to tell you the truth I don't want to fiddle with it and spoil it)

 

[David19800]

I let the latest version of Memtest86 (7.3) running for 14 hours and I had 0 errors.

It is weird.
How is it possible to have your CPU in its registered speed (3300) and have errors, while the overclocked run (4000) is without an error whatsoever.