how long to run memtest86 v3 ?

[Obelix]

Hi. Does anyone know how long to run memtest86 v3 to find out whether the memory module is good or bad?
Thanks.

 

[beatle]

I run mine for about 8-10 hours before I'm convinced.

 

[Obelix]

If getting errors, then how many errors are acceptable or if a pair of memory is good then it should not be any errors?Thanks.

 

[SpideyCU]

There shouldn't be any errors if it's good. I, and many others, simply let it run overnight so that it gathers up around 20-30 complete sets. That way you can tell what's going on.

 

[Jeff7]

If you get any errors at all, either the memory's bad, or else the timings are set too fast (if overclocking). If it runs at its rated timings, at its rated voltage without any errors, it's good.

 

[Obelix]

Thanks the replies. I have a P4P800DLX, P4 2.8C and Corsair TWIX512-3700. Setting is 3-4-4-8 as recommeded by Corsair but memtest reports numerous errors. I thought the memory is bad so exchanged to Kingston HyperX3500 and duplicated the same problems. The Kingston is rated at CL2 but I lowered the latency to 3-4-4-8 as well but did not help. But when I installed memory from my second computer, a pair of Samsung PC2700 then my system is very stable even at 2.5-3-3-6 with memtest reported no error after 8 hours. With Corsair and Kingston modules, I started having problems at 3 minutes and 2 seconds into the test, my system just hung there. Can it be a bad motherboard then or this board can only handle PC3200 CL3 modules ?

 

[MARMADUKE]

SpideyCU
Jeff7

You guys are all wrong!
memtest errors does not always mean that your ram is bad!

To help with troubleshooting an instability problem that you suspect may be caused by your computers memory subsystem, we recommend using a free utility called Memtest86 to test your computers memory rather than Windows based tools. Unlike Windows based diagnostic tools like Norton Systemworks, Memtest86 runs on its own Operating System so you can be sure that any miscellaneous Operating System problems aren't the cause of any problems. Windows based hardware diagnostic utilities like Norton Systemworks often falsely reports or misidentifies problematic hardware. We've received false memory complaints from customers that had Windows based hardware diagnostic utilities that reported memory errors. Yet they test fine when we test them with Memtest86 or our $25,000 hardware based memory tester. As an independent technician I would loathe the times when I had to work on computers that were loaded with Windows based diagnostic software. They always caused more problems than they fixed! Windows based diagnostic programs are a very very bad idea. You've got too many drivers, and other software programs running at the same time to allow for an accurate diagnoses of computer hardware problems.

Please be aware that not all errors reported by Memtest86 are due to bad memory. The test implicitly tests the CPU, L1 and L2 caches as well as the motherboard. So if the memory diagnostic software reports errors, keep in mind that this doesn't mean that there is definitely a problem with the memory module as other computer problems can cause a memory module to fail testing. It's possible that there is an incorrectly set BIOS setting, other hardware problems that are causing the memory test to fail, or the computer is accidentally overclocked higher than you thought. There is of course the possibility that a memory module is bad but you can only be sure of that if the BIOS settings are checked and other hardware problems are ruled out.

If Memtest86 reports errors, the best way to avoid incorrectly diagnosing the problem as being caused by a bad memory module is to swap in a different memory module. If you don't have a different memory module to troubleshoot with, or if swapping out the memory doesn't help, remove all unnecessary devices from the computer (all you need to run the test is a motherboard, CPU, floppy drive, power supply, video card, and only test one memory module at a time). If that troubleshooting step doesn't help then try swapping the power supply, video card, memory module, and CPU if possible. If removing or swapping devices did help, re-install them one at a time to find the culprit. If removing or swapping components doesn't help, then the memory module should be replaced.