Memtest not showing all installed modules in show info

[RussTech]

The last week my PC has BSOD 3 times overnight pointing to possible memory issues. The PC is around 4 years old and has been stable.

The first test with all 4 modules installed flooded with errors.

The BIOS is detecting all 4 8GB modules. In HWinfo on windows, it was only showing 3 modules, but 32 GB total. Windows Task manager shows 32 GB as well. In Memtest 86 V8.4 Free, it only sees 3 modules in the memory info section, but also shows 32 GB total during a test. Has anyone determined the root cause to an issue like this? Failed module or failed mobo?

I'm currently running tests against each single module. I didn't save the original errors, so I wont be able to attach them unless one of the modules fails.

[David (PassMark)]

Might be a failure of the SPD module on the RAM stick or the connection to the SMBus.

So while the memory is still installed, it might not be responding to queries via the SMBus (the system management bus, which is a two wires that run from the CPU to the RAM stick via the motherboard).

[RussTech]

Thanks!
Yup... I'm leaning towards SPD failure on the module. it was the last module I tested, and it had errors running at it's rated speed (1866) and crashed memtest. the bios reset the ram profile to 1333 and then I had no errors.

When that module was the only module installed and I ran the get SPD information it displayed an error "cannot read SPD information" that module didn't read correct in any of the slots, and all of the other modules are reading okay. So I'm a little more confident it's the module and not the mobo.

Feature idea: when multiple memory modules are installed and a single RAM module's SPD cannot be read, display that warning in the list of modules.

[David (PassMark)]

In the paid pro software there are some config options for this.
https://www.memtest86.com/tech_configuring-memtest.html

In particular this does exactly what you need
CHECKMEMSPDSIZE