Memtest86 CR

My question is specifically about the Memtest86 diagnostic utility, which I know is software rather than hardware but I reasoned that the hardware forum members would be a lot more familiar with it.

I ran a test on a computer with 4 sticks of RAM (1GB, and 3x 2GB) overnight and found 1000 errors. What I found interesting was that the errors per pass formed a Bell Graph - zero on the first pass, a few on the next, more on the next etc, then peaking on the 5th pass, but then getting gradually less for each subsequent pass. This seemed very odd, as I expected errors to either be roughly the same on each pass, or to be random.

In any case, I next wanted to find out how to scroll through the results to see if the errors were clustered around any memory ranges. At the bottom of the screen, Memtest86 handily states:
(ESC)exit (c) configuration (SP) scroll_lock (CR)scroll_unlock

So I assumed I'd have to unlock scrolling, then tap up or down to navigate through them. Unfortunately I just can't figure out how to do that! I've wondered if 'CR' refers to the CTRL key, so I've attempted both CTRLs, CTRL and R, and CTRL SHIFT R without any success; I've tried pressing C and R together, SHIFT C and R; I've hunted for a console to type CR in as a command; and yes, I've even tried hitting the Scroll Lock button on the keyboard, but nothing seems to work!

How on earth do you scroll in Memtest, and what are the SP and CR commands?

 

Don't waste your time. The minute memtest reports one error, stop the test. You can correctly assume there is a problem with the memory.
Run the test with only 1 stick of RAM in the computer until you discover the bad stick(s).

 

sp=space...cr=carriage return or enter ...

 

Unusual RAM set up. Hardly surprising you got a "result" from memtest86.

How many DIMM slots?

What is the SPD of "all" modules?

Settings in BIOS?

Bell curve can be good to "observe" but it has to be meaningful. It looks like your RAM set-up could readily skew DATA, produce "some" results but not a fair/random measure.

 

That's it! Thank you! I knew it would be something obvious I just couldn't for the life of me figure it out. I see now that it's unlocked by default, so hitting Return doesn't change anything unless you've first hit Space. I've since thrown out the bad memory module so I can't see how to scroll through the errors when it's unlocked. But as it's unlocked by default, and I know I must have tried PG UP/DOWN and the arrow keys, how do you navigate the report?

Yes it was a little unusual. I noticed that the computer came with 7 GB straight from the store - 3 of the exact same size/make/etc, and 1 x 1GB module from a different manufacturer.

4 DIMM slots in total, all filled.

SPD and BIOS memory settings were all set to their default or automatic values, but I don't remember what they were (and no longer have access to that computer).


If you were trying to troubleshoot the memory then rest assured that that particular memory module was clearly bad. With all 4 memory modules I received errors, with just one of each of the three working modules I received 0 errors, and with just the bad module I received errors once again. I used 5 passes for each test, 2 different slots for each memory module, and incidentally the faulty module was one of the 3 identical modules.

I mainly wanted to scroll through the results out of interest, but also it might help me isolate the faulty module faster next time. Perhaps if I can find a pattern in where the errors occur in the results page, then I can make an educated guess which module is faulty, and narrow my search to that one straight away.