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MemTest64 or MemTest86 ?

Joined
Sep 21, 2022
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Hi everyone. I would like to test my RAM without having to take it out of the PC and testing each stick for a long period of time. So how should I test my ram ? Should I use MemTest64 downloaded from here and run it from Windows desktop, or should I use another MemTest (Memtest86?) and run it from USB before boot? Will any of those tests be at least relatively good for testing all sticks of RAM at once? Thanks... and I really don't want to take out any parts of my PC right now or until I have to replace the motherboard. I only use my PC for playing anime games and watching anime anyway.
 
Been a while since had no need need to run memtest. Memtest64 is what I'd recommend, however from USB on boot, hmm, now checked looks like memtest64 does not have USB boot option.
Then there is also W10 built in diagnostic, should work just as well
W10 mem diagnostic
 
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you could download testmem5 (easier to use than the free version of memtest where you have to open it 15 times to test all of your ram)
it's from my experience faster than memtest (and if you're overclocking y-cruncher is a better choice)
 
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Memtest86, especially the latest version is excellent. Not sure why people complain about it, but it does it's work perfectly. If you have a RAM problem, Memtest86 will find it.
^^^This^^^ Just make sure you get the right one. There are several memory testers out there with very similar names. Ensure you get PassMark’s MemTest86. Allow the diagnostics to run for several passes or even overnight. You should have no reported errors – not even one. Please note the latest versions are for UEFI motherboards only. V4, available on same download page, is for legacy BIOS platforms.

Note, however, while software-based RAM diagnostic tools are good, none are 100% conclusive. If they report any errors, even one, the RAM is bad. While rare, on occasion they will report no problems, yet the RAM still fails in use, and/or when paired with other RAM. So, swapping in all new RAM is often the best test. But of course, not everyone has a bunch of spare RAM laying around so, if able, you might try running with just a single RAM stick to see if it fails. Repeat process with remaining modules, hopefully identifying the bad stick through a process of elimination. Just be sure to unplug the computer from the wall (and remove the battery if a notebook) and touch bare metal of the case interior BEFORE reaching for the RAM to discharge any destructive static in your body.

To conclusively test your RAM, you need to use sophisticated and very expensive test equipment, like this $2,495 Memory Tester (and that's for the cheap model)! So it is usually easier (and cheaper!) to swap in known good RAM and see what happens.
 
Thank you very much, will try it too then.
I forgot the link in my above post. I only use Memtest86 from the official open-source site;
This is the single most reliable software memory diag utility available.

Note, however, while software-based RAM diagnostic tools are good, none are 100% conclusive. If they report any errors, even one, the RAM is bad. While rare, on occasion they will report no problems, yet the RAM still fails in use, and/or when paired with other RAM.
While that can be true in some instances with some memory testing utilities, memtest86 from the link above runs in L2 or L3 cache on CPU and can therefore reliably test the entire memory address space and conduct a variety of tests most others can not. This is because it only runs from a boot-time loader and is self-contained. It is not running within another operating system. Additionally, Passmark's current version boot-time loader requires UEFI and will not run on legacy systems. They do make older versions available, but it's better to have an all in one utility.

The official Memtest86 is best.
 
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I stopped using Memtes86 when DDR5 came out because it caught nothing at all. its alright for DDR4, but things still get by pretty easily.
 
I stopped using Memtes86 when DDR5 came out because it caught nothing at all. its alright for DDR4, but things still get by pretty easily.
Which one? The official version or someone elses? I ask because the official version fully supports DDR5. DDR5-7200 certification is on the front page.
Memtest86FrontPage.jpg
 
Which one? The official version or someone elses? I ask because the official version fully supports DDR5. DDR5-7200 certification is on the front page.
It was the Pro version 7.X . Confusing that now they reverted back to 6 and my ASUS Z790 come with V9 in the BIOS. Which also doesn't catch nothing.

Support is easy. It boots and runs.
 
It was the Pro version 7.X . Confusing that now they reverted back to 6 and my ASUS Z790 come with V9 in the BIOS. Which also doesn't catch nothing.

Support is easy. It boots and runs.
What? What Pro version are we talking about?

Either way, the official version is the one I use and recommend for everyone.
 
The one you can pay for. its the same as free but I think it has a few extra tests and you can select only certain ones to run instead having to manually skip the ones you don't care for.
From here?
There is no paid version. Are you taking about Passmarks version? It's not the same thing. The official version is the better choice.
 
I would recommend testmem5 for everyone. However that doesn't help if you A) can't get into windows or B) the system is already unstable. So Memtest86 will at least tell you the memory is throwing big errors, but not the silent ones that make your games crash and OS unstable.

From here?
There is no paid version. Are you taking about Passmarks version? It's not the same thing. The official version is the better choice.
Passmark owns Memtest86 now from what I remember and the original one is dissolved. If Memtest86 lives on as open-source again, it isn't the same program anymore. Which makes sense why you are saying its good, because we are talking about 2 different programs that happen to have the same name. Official is Passmark now. What you link is now considered the alternative.
 
Is it best or even advisable to reduce core clocks to stock before running memtest?
 
I would recommend testmem5 for everyone. However that doesn't help if you A) can't get into windows or B) the system is already unstable.
System Memory testing should never be done within an Operating System, whether Windows, Linux or anything else.
but not the silent ones that make your games crash and OS unstable.
Not true. The official version of Memtest86 will diagnose all errors. This is why having two different programs with effectively the same name is such a pain in the neck.

Passmark owns Memtest86 now
No, they don't. If you visit the site I linked you see this. Passmark's version, while ok, is just a hybrid, bastardized version.

Is it best or even advisable to reduce core clocks to stock before running memtest?
Always restore to stock. Never run any diagnostic utilities while overclocking. That is asking for problems. If you're OCing and you get errors, the very first thing one should do is set everything back to stock. If the problem goes away, you know your OC was unstable. If the problem persists, you know you need to test further.
 
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How do people with 64 GiB or worse 128 GiB of RAM ever test it? It takes literally 8 to 10 hrs. to test 32 GiB of system RAM, I shudder to think how long it would take to test 64 GiB or 128 GiB of system RAM -- even with DDR5.
 
How do people with 64 GiB or worse 128 GiB of RAM ever test it? It takes literally 8 to 10 hrs. to test 32 GiB of system RAM, I shudder to think how long it would take to test 64 GiB or 128 GiB of system RAM -- even with DDR5.
They just do. It's a time-consuming process. There is no fast way to completely test large amounts of memory. What often happens is all of the RAM is swapped out for new RAM and then each stick is tested one at a time until the bad one is found. That's how we(the lab I work at) do it at any rate. This minimizes downtime. Our current servers have 384GB of RAM per server blade and the rest have 256GB or 128GB.
 
System Memory testing should never be done within an Operating System, whether Windows, Linux or anything else.
If your going to run it in windows, use memtest5. It's better. Only thing memtest86 has going for it is that you can boot to it without having to corrupt the OS. That's if it catches any errors.... The amount of times even with DDR4 that it "passed" and couldn't even boot into windows... I wish I had a running count. Its a good 30+. Now I just use a spare OS drive. Best of both worlds.

 
I stand by what I said. No software based memory tester is 100% conclusive. The only consistent conclusion is if they report an error, the RAM is bad. But RAM can still pass the most rigorous tests, and still fail when put in real-world use, especially when paired with other sticks. So it is often best, just like with power supplies, to swap in all new (or known good) RAM for conclusive testing.

I do agree, however, that testing outside of the OS environment is best.

How do people with 64 GiB or worse 128 GiB of RAM ever test it? It takes literally 8 to 10 hrs.
They just do. It's a time-consuming process. There is no fast way to completely test large amounts of memory. What often happens is all of the RAM is swapped out for new RAM... .
Right. There's no quick way to test RAM - at least with any real assurance the test results are reliable. I typically tell folks to just let it run overnight, for several passes.

It boils down to "mission requirements" or "personal choice". When downtime costs the company money, or compromises a critical/sensitive mission or service, you swap in known good RAM and put the computer back in service as quickly as possible. Then test the RAM, "offline" later.
 
From here?
There is no paid version. Are you taking about Passmarks version? It's not the same thing. The official version is the better choice.
Hi,
Yeah I've posted that one before and got slack around here saying it wasn't any good on ddr4 :eek:
Seemed fine for me using the boot to cd test from an old sevenforums tutorial think I still have the cd :laugh:

RAM - Test with Memtest86+ - Windows 7 Help Forums

Linux bash in windows is also supposed to be okay got that info from jpmboy on ocn
I've never used it but it was mostly for stability not for finding bad sticks like metest86+ is good for.
 
Yeah I've posted that one before and got slack around here saying it wasn't any good on ddr4
It's been updated relatively recently.
 
Yeah I've posted that one before and got slack around here saying it wasn't any good on ddr4
Yeah, well people have their favorites and sadly, some are intolerant of and often will lash out at others who have a different favorite or opinion. :(

As I noted, I like the one from PassMark, and so do others, as seen here. Personally, I don't believe it matters. None are conclusive.
 
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