Have you ever experienced single bit RAM errors?

[birdie]

Don't know what hit me today but I decided to run MemTest86+ 5.0.1 (after running MemTest86 8.3 UEFI) on my Ryzen 7 3700X system. It reported a single bit error for test 6 (Moving inversions, random pattern). I was surprised so much I ran this exact test three more times - no extra errors were reported.

I presume it was a cosmic ray which flipped a single bit but in my 25+ years of using PCs this has never happened before.

How do I know it's a single bit? Check the image:

0xfd and 0x7d differ exactly in one bit.

In binary that would be: 1111 1101 and 0111 1101.

Have you ever experienced anything like that?

 

[sch]

I registered specifically to reply.

One employee reported random BSODs a handful of times a week, often while installing software. Ran memtest86 and found this weird single bit flip issue:

My situation is probably a bit different than OP's because the issue is recurrently happening at the 10th bit, persisting across multiple reboots with different sticks of memory. I'm strongly suspecting MB or CPU issue at this point; probably an unreliable via/trace or something like that.

 

[unwind-protect]

I never had memtest86 complain about anything if it wasn't broken-broken.

 

[eidairaman1]

I registered specifically to reply.

One employee reported random BSODs a handful of times a week, often while installing software. Ran memtest86 and found this weird single bit flip issue:

View attachment 361532

My situation is probably a bit different than OP's because the issue is recurrently happening at the 10th bit, persisting across multiple reboots with different sticks of memory. I'm strongly suspecting MB or CPU issue at this point; probably an unreliable via/trace or something like that.

Ok and what is all the ram that has been tried?

Corsair rarely works in AM4...

 

[sch]

Ok and what is all the ram that has been tried?

Corsair rarely works in AM4...

Is that so? I've bought plenty of Corsair LPX for use with AM4, and this is the first time I've ran into such an issue. Furthermore, if this were to be true, I'd expect the setup to be "broken-broken" rather than a single bit flip like this.

I tried a stick of Kingston 16G 3200MHz today, saw the same thing so yeah. I'm requesting an RMA on the MB as we speak, since I think that's more likely to be the source of the problem than the CPU.