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Re: question about memtest86+




On 23/08/2018 09:58, Long Wind wrote:
i install memtest86+ of stretch to test memory
i don't see any error msg, but after a few minutes, it shutdown my PC
does that mean my memory is bad?
i read manual of memtest86+, can't find explaination

Uncommanded shutdowns may be caused by overheating. What is your CPU temperature under load? Your BIOS may shut your computer down if a temperature limit is exceeded. Manufacturer? Laptop? Model? CPU? BIOS version?

I use and recommend memtester, which can be run after a normal boot ("userspace"). I found that multiple concurrent instances of memtester detected memory problems not found by memtest86+. Run memtester as root so it can memlock. Because memtester runs after a normal boot, you can use a desktop temperature monitoring tool. I use the Xfce sensors applet polling at one second intervals, and this script:

#!/bin/bash
tmax=0
while true; do
    t=$((`cat /sys/class/hwmon/hwmon2/temp1_input`/1000))
    tmax=$((t>tmax?t:tmax))
    echo "`date '+%T'`: $t / $tmax"
    sleep 1
done

I also use thermald to limit CPU temperature (but my problem was not temperature). I use a custom service file to reduce the polling interval to one second.

Another useful test tool is mprime <https://www.mersenne.org/download/> (AKA Prime95 on Windows). Be sure to disable AVX with "CpuSupportsAVX=0" in local.txt because synthetic AVX tests can be used to generate excessive and unrealistic amounts of heat.

Kind regards,

--
Ben Caradoc-Davies <ben@xxxxxxxxxxxx>
Director
Transient Software Limited <https://transient.nz/>
New Zealand