Memtest 7.4 not seing my 32GB RAM

[LeKeiser]

Hello all,
I see there are already some threads about similar problems but they all seem to use an older version of Memtest, so I'm starting this one in case other people have the same issue.
I have a Ryzen 1700x running on a Gigabyte Gaming 3 motherboard, with 32GB RAM 2400 (4x8GB)
Memtest 7.4 only sees 16GB and test only those 16GB. Yet in the log file, the 4 RAM slots are described properly.
I don't understand why then the test doesn't run on the whole 32GB...

Also this is weird (or scary?), I've run the the test for 4 hours, no error. I've run it overnght, and I got an error (on 5 I can't rememeber) on a specific CPU (2) with test 6. I see lots of people have had errors with this test 6, so I was wondering if there wasn't a bug somewhere or if I really have a hardware issue with my RAM... Why a specific CPU?

Thanx for your comments
.

[David (PassMark)]

Some motherboards require slots to be populated in a certain order. But the Gigabyte Gaming 3 only has 4 slots. So that isn't the problem.
Are all the RAM sticks of the same make and model with same timings?
Is the BIOS firmware up to date?
Did you try removing and re-inserting the RAM sticks.
Did you try two sticks at a time in each pair of slots to see if one stick or slot is bad.

There are different methods for detecting total RAM, vs detecting the RAM stick details (called SPD data). The later is done via the SMBus. So a memory stick can be faulty or not making good electrical connection, but still allow the SPD data to be read.

[LeKeiser]

Hello David,
Thank you for your answer
All the RAM sticks are of the same brand and same model, same timing.
I tried different BIOS, I've installed the latest stable one and got errors during a test I ran last night (more in this post)
I haven't tried to remove and reinstall the sticks because:
1) Windows 10 64bits sees the 32GB, physical, but only 16GB "usable"...
2) CPU-Z, Specci, they both see the 32GB sticsk, one in each slot, and I have the correct info. I understand the SPD information being read, but... Only HWInfo doesn't see more than 16GB also but sees all the slots filled up.
3) the BIOS is set up with the XMP profile, but even if it's not configured this way, Memtest86 still sees only 16GB.
But if I'm not mistaken, the logs that I got shows that all the slots are filled too.

I have run a parallel CPU test standard, 4 times, and I got zero error. I ran last night a Round Robin CPU test and got 11 errors on CPU 7, and the test was either stuck or still running this morning, but I couldn't ESC it, or use the C key (configuration) but CTRL/ALT/SUPPR did work. So I launched another CPU parallel test, 16 times, and will hopefully get the result later today after work.
I'm testing the RAM but I haven't had any problem with my computer, no BSOD whatsoever. I'm only concerned about the size I get in Windows Pro 64bits, and Memtest86 7.4