I have been told to accept one error with Memtest86+

Solution 1:

Straight from the Memtest86 author. I would push them to replace it. There should really be no errors at all.

If you have a relatively small number of failing addresses and only one or two bits in error you can be certain that the errors are valid. Also intermittent errors are without exception valid. Frequently memory vendors question if Memtest86 supports their particular memory type or a chipset. Memtest86 is designed to work with all memory types and all chipsets.

All valid memory errors should be corrected. It is possible that a particular error will never show up in normal operation. However, operating with marginal memory is risky and can result in data loss and even disk corruption. Even if there is no overt indication of problems you cannot assume that your system is unaffected. Sometimes intermittent errors can cause problems that do not show up for a long time. You can be sure that Murphy will get you if you know about a memory error and ignore it.

Solution 2:

It looks like only a single bit is being corrupted (i.e. not set to logic 1 when expected) at that address. If you can reproduce the error, the RAM is faulty. Even a reproducable 1-bit error is still an error, and could cause problems when using the computer.

Properly working memory should *never** have any errors, as a computer expects (and is why they crash when you have bad memory, as a safeguard; you can't reliably run a machine with bad memory, as the computer may execute corrupted instructions or provide/store corrupted data).

* over a long enough timespan, it's possible for DRAM bits to get corrupted from external sources like background radiation; the event is usually so rare most computers run Memtest for weeks without error. Also see the Stack Overflow question, "Cosmic Rays: what is the probability they will affect a program?".