I think a corrupt cpu cache would cause system crashes and corrupt data all the time...
This server runs only a single app, it's on FreeBSD 12.2. 6 other similar servers with similar hardware specs, also FreeBSD 12.2, same app, run just fine.
The app basically stores files to disk and writes their CRC at the same time.
About once per day, an invalid CRC gets calculated. About once per week, the app coredumps.
Coredump analysis by the app developper shows a random memory jump that shouldn't happen, but memory contents is fine. The app just jumps unexpectedly to a random location.
I am replacing the server entirely but I want to be able to test it after I take it off production and identify the issue better.
Before putting it in production I just tested with Memtest86+ pro which showed no errors after 4 passes.