Bit fade on HP Z400 EEC DIMMS

[rhb]

I have 3x 4 slot Z400s and 1x 6 slot Z400. After 9-10 years of operation the 6 slot system is displaying serious bit fade issues with 6x HP 2 GB DIMMs.

Memtest86 4.3.7 ISO passes the 6 slot and a 4 slot which has had no issues. Memtestx86+ 5.31b fails both whether built from source or the ISO. Both systems pass all other tests by all 3 versions.

I first encountered bit fade 30 years ago on a Sun system which could access the tape drive immediately after booting, but if the system were left idle for 24 hours repeating the same tape operation would kernel panic the system. In my case this was a personal workstation, but on a server this would be a really serious issue.

In my view a proper bit fade test would take an upper and lower time limit, start at the minimum time between write and read and after each successful read, double the time since the write until it reached the user specified maximum. Once the time required to write all memory installed before the read was scheduled was reached it should write all memory and simply sleep and read until it timed out or encountered an error.

Reg

[David (PassMark)]

Why isn't ECC picking up the errors?
i.e. are you sure the errors are real errors?

In the Paid for version of the software there is a config file setting you can change, BITFADESECS.
So you can make the test last for about a week of you want.

BITFADESECS = Specifies the sleep time in seconds to use for the Bit Fade test (Test 10). By default, the sleep time is 300 seconds (5 minutes). This value must be between 180 seconds (3 minutes) and 600,000 seconds (10,000 minutes).