Testing your RAM with Memtest86+

So you just got your shiny new RAM, and you can't wait to upgrade your computer. Congratulations! You've been through the decision making process, scraped up the cash, placed the order, eagerly followed the tracking number, and now it's finally in your hands! This is what you've been waiting for!

But before you install those new sticks, close everything up and ride off into the sunset, there's one thing you really, REALLY should do first...

TEST THAT RAM

The sad fact is that RAM can easily get damaged, for a variety of reasons: manufacturing, packing, shipping, or even installing. Most damage comes from static electricity, and the effects of such damage can result in a system that randomly reboots once in a while, or one that won't boot at all. The latter is pretty obvious, but the former is usually blamed on the OS or something else. (Bad RAM is frequently the true cause of problems with Windows)

In any case, you should ALWAYS test your new RAM thoroughly before considering yourself "done" with it. It's also very important to do this as soon as you get it, so you won't miss the return deadline date. A lot of RAM has a good warranty on it, so that's also an option if you missed the window; you'll just have to deal with the manufacturer directly (which isn't really that bad, at least when I dealt with OCZ).

Testing
The best package out there for testing is called memtest86+. The original project, memtest86 (note the missing "+" sign), is still around, but was not updated for a long time. So the memtest86+ guys took over.

Memtest86+ is very easy to use. All you need to do is:

1. Download the file. I'm going to walk through using the "Pre-Compiled Bootable ISO (.zip)" file. You can get that from this page.
   
2. Unzip the file. There's only 1 file in there, called "memtest86+-X.YY.iso"
   
3. Burn the ISO file to CD. This is the potentially tricky part. An ISO file is a disc image, and cannot be burned directly to a CD. Your CD recording tool should have an option like "Burn image to CD" or something like that. If you can't find it, you can try the free ISO Recorder powertoy. After you burn the CD, if you put it back in the drive and see the file "memtest86+-X.YY.iso" listed, you've done it wrong
   
4. Shut down your computer completely, then unplug it. DO NOT DO THIS IN SLEEP OR HIBERNATE MODE!!!
   
5. I recommend testing the modules one at a time, so if one is bad, it's easy to know which one! Take out all but one of the RAM modules.
   
6. Plug in the computer, put the CD in the drive and reboot. Make sure it boots off the CD, not the hard drive. You should see a blue screen with a green bar on the top that says: "Memtest86+". There are screen shots on the memtest86+ web site so you can get an idea.
   
7. Now, you wait for the test! The test will run forever until you stop it. You should run it for at least 1 full pass, more if you have the time.
   
8. Once the test is done for that RAM module, shut down, unplug, take out the module you just tested, put in the new one, and test again.

Running the test will take some time, and it's directly dependent on how much RAM you have. One full pass of tests took 45 minutes on my system while testing 2GB of RAM. Don't worry about the time -- just start a test before you go eat dinner or something. My experience has been that bad RAM shows up pretty quickly, but it's worth it to run at least one full pass. I often let it run all evening if I'm off watching TV or something.

What am I looking at here?

• In the top-left, you'll see some information about your system, CPU, total RAM, Chipset, etc...
  
• In the top right, you'll see the overall progress of the tests. Memtest86+ runs many different tests on the RAM, and when it completes the whole battery of tests, that is considered one complete "pass". So the top bar is the progress of the whole "Pass", while the next "Test" bar is the progress of the current test. Underneath that "Test" bar is more information about the current test that's running.
  
• On the bottom half of the screen is information about the memory that it's testing. The most I really pay attention to here is the "WallTime" column, which shows you how long the tests have been running.

Dealing with Errors
If you get errors, it will be pretty obvious. The part of the screen that's currently blue and empty will fill up with RED error messages, you can't miss them. What the errors are really doesn't matter. All you need to know is that it's bad. A good RAM module should have zero errors.

At this point, all you can do is return the module to where you bought it, or get a replacement under warranty. There's no way to fix it, and there's no reason to live with it either. Do not put up with a bad module, get it replaced. Replacing it is the only way to make sure manufacturers don't get used to the idea that their customers will put up with bad quality.

Typically, all you need to say is "I tested it with memtest86+, and it was bad." Any memory manufacturer will know exactly what you're talking about, and shouldn't give you a hard time. Some places will cross-ship you a new one, while others will wait for you to send back the broken one before they'll replace it. That's just the way it is.

How important is this?
Personally, I've had about a 40% failure rate with the RAM I've purchased. Maybe I'm unlucky, or just have a lot of static electricity around, but I've almost always had to return at least one of the modules I've received.

RAM is one of the really base components in your system, and if it's bad, you will not be able to have a stable system, period.

If you have other questions, you can take a look at the memtest86+ F.A.Q.

 

I always test the memory I buy with memtest. I had a problem with DDR1 stick I bought a while ago, RMA'ed and it was fine since. Recently, like 3 months ago I got 4 pairs of DDR2 memory, all worked fine. I did get errors in memtest when I put any of those sticks into the first slot on the motherboard which turned out to be mobo's fault. So yeah, with memtest you not only check your memory but also other related components (cpu, for example, as I hear memtest is also good for testing cpu overclocks for stability).

 

You always put together a nice guide Orev. I've been referring lots of people lately to memtest86+. Now I can just refer people to this link.

BTW, my favorite free burning utility is "imgburn" from imgburn.com

I thought I would add that not all blank CD/DVD media is created equal. Most any will do the job if you are in a pinch, but here are a few tips...

For best results, you should get Verbatim CDs. If for some reason you have trouble finding Verbatim, then another good choice would be Fujifiln, Maxell, or Sony BUT you have to check the label (usually located by the bar code) to make sure it says "Made in Japan" That's the good stuff. If it says "Made in Taiwan" or somewhere else. Don't get it.

Cds are usually rated at very high speeds like 32x or 52x. You will get a better quality burn if you slow that down to something like 16x. Most burning applications have a drop down menu which allows you to adjust the burning speed.

Memtest86+ is a small application and will fit fine on a CD. If you ever need to burn something onto a DVD, similar rules apply...

Buy Verbatim or buy fuji, maxell, or sony that are "Made in Japan". I personally prefer the DVD+R variety over the DVD-R variety. Get DVD media that is rated for a speed that your DVD burner is capable of burning. Most DVD burners made in the past few years are capable of burning a DVD+R at 8x speed. That is what I usually buy. Your DVD burning application might attempt to burn much faster than the speed that the media is rated. For DVD, media it is best to manually set the burn speed to equal the rated speed (or slightly less). It has been proven that very low burn speeds or very high burn speeds can produce errors.

Good Luck!

 

For first time memtest users like me, it would be a good idea to check out the FAQ before running the test.

Thanks to orev for the guide, and stallen for helping me out with everything else. Much appreciated.

 

Thanks for the FAQ link. Added it to the guide.

 

Can you run memtest on apple hardware? I.e. a MBP?

 

Hey Orev- Thanks for the great tutorial. I just added 2 Gigs to mt 1520 and ran Memtest86+. I unplugged the laptop and ran it. It went through 3 passes and the battery died on the 4th pass. I did not see any errors at all uptill the point that it died. Do I still need to run more passes and would the computer dying while running the test on the 4th pass mess with anything? I.E. Should I run memtest again (Running on power supply?)

 

I'm not sure. You can check out the faq link, maybe they talk about it. Also, there is some information on Testing RAM on macrumors.com.

 

If the battery went dead while it was running, it shouldn't cause any problems (though I wonder why you would do that?) You should definitely get through at least one pass, and 2 is better. More than that is a good stress test for it, but by that point you can be reasonably sure that the RAM is OK.

 

Thanks Orev - I was running it on battery because I thought that it would take 45mins tops and my battery has a life of 3+ hours. didnt know that it did multiple pass throughs.

 

Yeah, once you start it, it keeps going until you stop it

 

Hey, I ran the test for only 17 minutes because I didn't know it was going to take that long...

I had 0 errors after I exited out, do you think I should be fine?

 

It's a good idea to get through at least 1 whole pass of tests. For your notebook specs, it'll probably take almost an hour. Just run it when you have time to go off an do something else.

 

Thanks for the guide Orev very interesting .

 

is this 64bit or x86? Reason for asking is to know the maximum amount of physical memory tested...

 

I've also asked that question to the people who wrote it, and so far the answer is "it will test all of the RAM in your system". I then replied, asking specifically about 32bit/4GB limits, and have not yet heard back.

 

Either way, there's a small part of the RAM that cannot be tested by the software because of the BIOS as stated in the FAQ:
"- Which memory is tested?

As much as possible of the system memory is tested. Unfortunately memtest86+
can usually not test all of the memory. The reason for this is that todays
processors and BIOSes have become so complex that they require a small
amount of memory to keep accounting data of the processor and BIOS state
respectively. If memtest were to write over these areas the state of the
processor or BIOS becomes invalid and it's behaviour unpredictable. Alas it
is also impossible to relocate these areas in the memory.

This means that a small area of your memory can not be tested by memtest.
If this part of the memory is defective you will know soon enough though as
the processor, parts of the processor or the BIOS simply won't work
correctly if this part of your memory is defective. Do realise though that
in very rare cases memtest will show no errors even though the module is
defective, not because memtest can't detect the error, but because memtest
can't test the area the error is located in."

 

This might sound kind of extreme but I bet there is a work around for that area that "can't be tested". What if you tested the RAM modules with memtest86+ as usual, then physically pull out the RAM and swap locations (put them in opposite slots). Then run memtest86+ again.

I think the chances of the BIOS using the exact same area of RAM would be pretty slim after swapping locations.

 

Smart guy! I asked that too. Here's the thread about it:
Max RAM supported?

 

Ok, i didnt see your thread orev. Obviously everyone is already aware of the BIOS using up some of the ram during testing. Please disregard my previous post above.

So in that thread, wichetael basically implied that memory modules should not only be tested individually, but also as a pair in the system for compatibility? Is this correct?

 

Several months ago I tested the RAM in my notebook with memtest86+ and within the 2 or 3 pass I got some error messages. After that I changed the HD and also 'swapped' the RAM memory chips (changed from slot), and just yesterday ran memtest86+ again: it showed no errors after 7 passes (~3 hours).

Is it safe to just keep the RAM going? Or should I run a 'third' run?

EDIT: Forgot to mention but in the meanwhile period I updated the BIOS as well.

Thanks.
Joe.

 

I had bad ram that would not give errors in Memtest86+. Once I switched the ram, all the crashes and weird problems disappeared. Memtest86+ does not detect 100% of the errors, but it is a good place to start.

 

I ordered laptop memory, and my laptop wont be here for awhile. My fathers laptop supports DDR2 533, whereas the memory I ordered is DDR2 667. Is it possible to test my memory in my fathers laptop?

 

It will probably work OK, as long as the modules fit in the laptop. They will just be a little slower, but it shouldn't affect the test.

 

I don't mind if its slower, I just want to make sure they work.

 

I can't get Memtest86+ to boot.
I have no idea why. I used ISO recorder to burn it to a CD and I have my CD-ROM drive as number 1 in my boot order (under my BIOS). It just doesn't run the program and boots Window like it always does. I don't get it.

 

actually depending on the laptop, if it supports 667 speeds it may use it as the faster speed.

 

Is there a key you can press to bring up a boot menu? Try that instead of changing the BIOS settings. Otherwise, try the disc in another computer if you can. Maybe the disc didn't burn correctly. If all else fails, you could remove the hard disk before trying to boot to the CD.

 

I got it working. I guess it just didn't burn correctly the first time, I tried on another CD and it worked.

So does this Memtest86+ cycle over and over? I let it run for a couple of hours (while I was gone out) and when I came back it was still going. It said 2 Pass and had no errors but it's still testing. So does this mean it went through the cycle twice and didn't find any errors and it's just testing it again and again?

 

Yes, it just runs and runs. You should try to get through at least 1 pass. More than one is even better.

 

Awesome. Well it went through 2 and didn't get any errors. So my new RAM should be fine!
The only bad news is that the RAM I bought went on special today (on the website I bought it from) so I could have saved 25$ if I had waited until today to buy it! But then I wouldn't have it now, haha oh well!
Thanks for the help everyone.

 

Ditto on the Imgburn. Double clicking on the Memtest zip file opened the program automatically.

 

How come the ISO i put on the CD when booted simply loads the regular windows Memory Diagnostics Tool, it doesn't say Memtest86+ anywhere.

 

Are you sure your laptop is booting from the CD? Or maybe you have the Windows install CD in the drive instead?

 

I would personally recommend doing the opposite of this. It would be better to test both modules together and THEN if you get errors take out one and test till you see if the problem is with just a single module or both. This method would be especially true for testing two modules of different brands. A lot of people buy their laptop with 1 DIMM installed and then buy another one aftermarket. Certain memory chips do not play as well with others and can cause memory related issues. They also may not want to run in dual channel mode together without causing problems. So in other words, test your memory based on how you're going to be using the laptop and then if you run into errors you can try to isolate the problem to see if it's a single DIMM or an issue of compatibility between the two.

Also, on top of running Memtest86+ I would suggest running Windows Memtest as well. It's a small memory testing program that runs from within Windows and puts the memory under heavy stress. The OS isn't loaded when you run Memtest86+ and so there can be a big difference there in finding errors because of the differential load the OS puts on the system when it's loaded into the memory. I've found that Windows Memtest usually detects errors much faster than the DOS version of Memtest86+ and I've also been able to run Memtest86+ for hours at a time without an error and then fail Windows Memtest. So I suggest trying out both if you really want to test your RAM. I come from a desktop overclocking standpoint with RAM where a single error can throw off testing so you have to be more thorough in your methods.

http://hcidesign.com/memtest/

It's normally suggested to let Windows Memtest run up to around 1,000% to get the most thorough test.

 

Errors can take hours before they show up. Sometimes they have to really heat up for a prolonged period before they cause an error. It's normally suggested to let Memtest86 run for at least 6-8 hours for proper memory diagnostics.

 

I just installed 2 sticks of 2GB RAM from Geil into my V1S, and when I ran Memtest86+ with both sticks in, it showed errors. Just out of curiosity, I tested with the Windows Memory Diagnostics, using 2 passes and full testing, and it found nothing.

How reliable is the Windows Memory Diagnostics, and has anyone ever had any "false positives" with Memtest86+?

 

I see there is a link to download memtest+ to run off usb key, in dos,but i dont see instructions on how to make usb key boot.

 

Using a CD is easier, because more (all?) laptops support booting from CD. If you know how to make your USB bootable, go ahead and use it.

 

Memtest86 is open source and has been around for a while. Being open source, that mean a lot of people have been able to look at it and debate about methods and fix problems. The Microsoft one is closed and who knows what they are doing. I'm sure the MS one is OK, but I would value memtest86 above the Microsoft one.

 

It may have already been mentioned by someone else in this thread but Memtest86 is actually more up to date than Memtest86+. There was even an updated alpha release on Dec 27th.

http://www.memtest86.com/

 

Yes, they have revived recently, and seem to be trying to make a business out of it. The project was basically asleep for YEARS, so they have lost a lot of credibility. Then they come back and try to get you to buy something that was for free. There's nothing wrong with that, but the 86+ project has been active for that whole time, so they gained more credibility during that time.

 

Hi I got a new 2GB OCZ pc-5300 RAM for my inspiron 1420 today.. I was really excited with the deadly offer I got for it.. Just $23 including shipping tax etc after a Google checkout. As advised in this thread I did a Memtest only with this new piece of RAM. It ran first 4 passes without any errors. While running the 5th Pass it showed me just one error. Well, I don't know what the error meant. but it was basically a single red line which with 1 error. Should I be sending this RAM back? If I had ran only 3 or 4 Passes I would have happily continued using it thinking that my RAM is error free.. but then how many passes should one typically do before you can ensure that your RAM is good? Would my machine be at risk if I continue to use this RAM? Please advise.

If I got to send it back does OCZ pays for the shipping? any ideas?

 

I would put it back in the machine and let the test run overnight, maybe even 24 hours. Then see what happens. I agree it's sort of on the edge. Most of the time you will need to pay shipping back to them, but they will pay the shipping for the replacement to you.

 

Hi I put it back into the other RAM slot in my machine and ran the test again over night. It ran some 16 passes. From the 4th pass onwards I could see some error. In total it reported that there is a total of 8 errors when I checked it up in the morning. But I happen to read from this website that memtest showing an error doesnt necessarily mean its a problem with the RAM. I am now confused. Can I call up OCZ and say your RAM is faulty and I need to return it because memtest86+ showed me errors? will they accept my claim?

If I choose to put up with this error and continue installing this ram in my machine and use it, what will be the repercussions on my machine? Please advise.

 

It is possible that the error can come from other places in the system, because when doing the testing it must also use other parts of the system, like CPU, northbridge chip, memory bus, etc... so it's hard to say specifically that it is the RAM. If I were you, I would call up OCZ and see what they say (or if you can still return it to the store where you bought it, then return it). You're better safe than sorry.

Problems it can cause could be system crashing or data corruption. On yours it might not happen that often, but consider that you have seen the error after running for a few hours. Do you often run your computer for a few hours during normal use?

 

I run my laptop almost every day for atleast 13-14 hours....!! very intensive daily use.. I bought this machine only a month ago. In the past I have purchased RAM and have used it without doing a test.. but this time.. I wanted to be a bit more careful.. and see where it has took me to... I guess I will call up OCZ.. I purchased it online from buy.com .. so I dont know if they will take it back and replace...

 

orev, you might want to add a bit to the original post:
Memtest is not exhaustive. It tests a few access patterns that covers as much as is reasonably possible in a short timeframe. But RAM errors may be extremely complex (you only get an error if this and this and this bit is set in this byte, and this exact other byte contains so and so, and you try to write to that third address".
So Memtest can never catch all errors (because it'd have to test an infinite number of combinations), and running Memtest without finding any errors does *not* mean that your RAM is ok. It just means that Memtest didn't find anything.
Which also means that if you're suspicious of your RAM, you might have to let Memtest run for *a long* time before it finds anything. A day or two isn't unheard of. (But of course, even then, it's still not guaranteed to find any errors, it's just more likely than if you let it run over dinner)

 

Blah, one of my new 2gb modules is faulty, turned up with 41 errors when i ran memtest with both new modules on. So i ran them individually one of modules had no errors so i put in the other one and it the errors showed up but only 28 this time. Wondering where the other 13 errors went...

I gotta admit though that my system is noticably running alot faster than before and hasnt given me any BSOD. Any chance this might be a false positive? or it just hindering its performance?

 

I don't believe that those 13 errors "magically disappeared" as you seem to think. Certain tests that memtest runs are random. Therefore, if I'm not mistaken, it might produce an error on one pass but not produce the same error (or same number of errors) on another pass. This is what I've come to understand. Someone who is better versed on the subject will correct me if I'm wrong.