Memtest86 Test 9
Cherie Trojak
MemTest86 executes a series of numbered test sections to check for errors. These test sections consist of a combination of test algorithm, data pattern and cache setting. The execution order for these tests were arranged so that errors will be detected as rapidly as possible. A description of each of the test sections follows:
If I encounter a situation where I suspect my machine's RAM might be going bad, I might need to launch memtest86+ to check it. How can I do this using Ubuntu? Are there different methods for launching it whether Ubuntu is already installed?
As you can see there are some options to choose from (this will vary from installation to insatllation), the one to look for is the third option in this screenshot i.e. Memory test (memtest86+), which will be there in the grub menu along with other options.
Here is an image (taken from here) showing that errors were encountered i.e. the test is failing in some memory locations (pointed out in the red portion) indicating the locations might have problems. If your memory does not have any problem then you won't get any red portion.
To use Ubuntu live USB for starting memtest86+ you might have to change boot order in BIOS or press some system specific (function) key to display one time boot menu and then (at least with Ubuntu 22.04 live media) choose legacy boot (not UEFI) for the USB media. Then there is Memtest in the Grub menu. Maybe with the latest Ubuntu release it is different and you can run memtest even if you use UEFI boot for the media since memtest86+ version 6 has UEFI support.
You are spot on, I actually managed to interrupt the auto-start of the test and navigate to settings and manually change the resolution. Once changed to either 1920x1080 or the native 2256x1504, the test screen now displays it properly.
PassMark suggests that this is a firmware issue, and further recommends purchasing the configurable version of memtest86+ to remediate it. If it really is a firmware issue, it may be worth pursuing a fix on the Framework side.
Hello,
Assume a 386 with 128KB L1 cache on the motherboard, the usual stuff. If one would like to test stability vs SRAM timing (find out the tightest cache timing the chips+motherboard are stable with), is memtest86+ an appropriate test to run?
Of course setting the timing way lower than what's possible results in obvious problems (no boot, frequent crashes etc) but for marginal situations where the system boots and problems occur only after extensive use (=a lot of time and "luck" needed to encounter them) would memtest86+ catch them or does it test only the RAM? If this is the case what would you recommend to stress test the cache?
The memtest86 implicitly exercises caches to some extent. However, most of its tests are deliberately written in a way to avoid reads/writes being cached/bufferred as it obviously defeats the purpose of the tool to test he RAM.
HCI memtest is way, way, way better from my experience. But it is for newer systems. It finds slightly flakey memory way, way, way, way, way, way faster than memtest86+ does.. if memtest86+ even finds problems at all.
Unfortunately it's a 386 so no quake or windows 9x (dos & win3x only) to run all the suggested tests. I'm considering temporarily using another hard disk to do a minimal install of win95 and try them though. I won't run a nuclear power plant with it but it's built to stay on the desk and get used so I'm trying to determine once and for all the best values where it's 100% stable and never touch it again until something breaks.
Testing cache specifically requires chipset programming that BIOSes use to determine how much cache is there etc.
Memtest86 has no such functionality and I'm not aware of any software that can do it.
Memtest86 actually has routines to detect caches, measure speed, sizes, etc. As mentioned above the main reason is that it is somewhat futile attempt of trying to avoid test data being cached as well as report it.
Most/all chipsets when off CPU caches were a thing actually have methods to force access to go exclusively into the cache, without touching RAM, essentially turning it into the RAM itself. Other methods assume that whatever you do in one spot remains in caches but you are still at the mercy of whowever the device does with cache and RAM interactions. Cache in at least some of the modern CPUs should be possible to put into a mode where it becomes directly accessable RAM, it certainly is possible in many non x86 architectures.
I've tried this on 2 different systems and no luck.One is a brand new Ryzen 3900XT CPU with ASRock B550 Extreme4 MotherboardAnd the other is an Intel Xeon E-2176G CPU with Supermicro X11SCA-F motherboard.
Here's a List of Motherboards with issues when running MemTest86 in multi-CPU selection modes, which is mostly not much up to date with newer hardware. The user from this post guesses that problems with his two Supermicro models of X10SAE and X10SLH-F may have the same problem but it happens after a long testing time of 30+ hours.
It is important that you do this, as not doing so could cause errors when running Memtest86. See below for examples of errors occurring when the CMOS is not cleared; these examples all use the same kit of memory:
If you are unsure of how to clear your motherboard CMOS, check the manual for your motherboard; some motherboards have a dedicated button for resetting BIOS to default, while others have jumpers you can use to reset to default.
Once you have cleared your motherboard CMOS, plug the USB drive with Memtest86 on it into your computer and power it on. You should not need to press anything; the test will automatically start after a countdown.
Memtest86 is a quick test, taking roughly 1 hour per 8GB of memory. However, this is dependent on the memory configuration. For example, a single stick of 16GB may take 2.5 hours or longer, compared to two 8GB modules taking 2 hours to test.
If you have multiple kits, make sure you test each kit individually, even if they have the same part number. This will help make sure that you do not have an issue of multiple kits not working together, as kits with the same part number sometimes do not run together due to not being in a supported configuration.
Once the test is completed, you will be asked if you want to save the test results to the USB drive as an HTML file. Make sure you save this file, as you will need to attach this file to a help ticket if you plan on returning the memory kits under warranty.
When Customer Support assists you with RAM issues, they may request that this test be completed with XMP disabled and at stock settings. If your memory kit is above 3600mHz or is on an older generation hardware (e.g. 2018 or earlier), please refer to this article for more information.
We recommend testing higher speed kits by individual module in order to make sure your CPU and motherboard combination can handle high speed memory. Higher speed kits are defined by platform; for example, 3200mHz with a Ryzen 1000 series chip is considered the high end of the platform, while many B550 boards can hit 4000mHz or higher easily.
Create a bootable Memtest86 USB drive using Etcher. Option Boot the USB drive and select the orange icon labeled "EFI". The current version of Memtest86 (v.8.2) only loops the tests four times unlike the older versions which could be looped much longer. The older v7.5 version is available here. Once Memtest86 boots, it is safe to remove the USB drive. FYI, It is not unusual for memory to fail the Row Hammer Test and doesn't necessarily mean the memory is bad. It just means the memory is vulnerable and can be "attacked" to gain root access.
I wasn't having any problems but I took it to an Apple store and they told me the memory failed during the diagnostics and I wanted to check myself. I'm no technician, but I didn't want to give them $200 for nothing. Besides, third party memory was added to the computer before I bought it, which could be the reason it is coming up with a fail. Thank you for your help
What other issues could cause it?
Could it be the fact that the old ram is 1333 and the new ram is 1600?
Could it be a hair or dust on one of the pins?
Should I return it and get all new RAM?
We need to get a bit specific here. The memtest86 program has different tests that it does, each testing different types of memory failures. Once it loops through all the tests it does a second pass of all the tests, then a third, etc. The failure will be in a specific test, and knowing which one would help us narrow down potential causes.
I am using it in a MSI X399 Gaming Pro Carbon AC motherboard, with a AMD Ryzen Threadripper 1950x CPU. I have two kits, and populated both kits in the slots specified by the motherboard manual (A2/B2/C2/D2). I initially used the A-XMP profile for 3000MHz. When running Passmark memtest86 v7.4, I would notice about four errors on Test #10. I kept dropping frequency, thinking a Ryzen compatibility issue, but even at default 2133MHz, I would get a handful of errors on Test #10. I then decide to test the two kits separately, installing in slots B2/D2, and running at default 2133MHz. One kit fails on Test #10 as above, while the other passes. So it looks like this one kit is bad. I would like a replacement, so I can run in quad-channel. Would like to setup advanced RMA.