Ram computer tester - Page 1
Forum section: electronics / projects

author: Aigor
author_rank: Contributor
timestamp: May 09, 2017, 03:48:07 pm
content: Hi, i'have an idea, could be possible build a standalone pc ram tester?My friend own a computer lab, he have a lot of simm and today i start to think about ram standalone tester.Could someone point me to some info about info on how dimm work?Or, someone has same idea?many thanks

author: bktemp
author_rank: Super Contributor
timestamp: May 09, 2017, 04:22:20 pm
content: Quote from: Aigor on May 09, 2017, 03:48:07 pmI assume you are talking about modern DDR3/DDR4 memories?It is possible, but very difficult.QuoteIf you have to ask such questions forget it.DDR3/4 operate at >1GHz. That requires carefully designed pcbs with at least 6 or 8 layers.In addition to that to need a processor or FPGA that drives the memory at such speeds with the correct timing. Even if you are able to build such a device, it will be really expensive, because you need to to a lot of tests to verify your timing, otherwise you won't know if the RAM is bad or the timing of your tester is incorrect.

author: Nusa
author_rank: Super Contributor
timestamp: May 09, 2017, 04:38:54 pm
content: Such things exist commercially and are easily found in a search, but I wouldn't bother.I'd just use a open frame PC with a motherboard that supports the RAM in question. Use a bootable flash drive with some of the many RAM testing programs that are available and you're good to go.

author: CJay
author_rank: Super Contributor
timestamp: May 09, 2017, 04:43:03 pm
content: Quote from: Nusa on May 09, 2017, 04:38:54 pmDon't know an awful lot of the tech bits around DDR3/4 etc but wouldn't a thorough test in such circumstances require a board that'd 'max out' the memory speed?I know the commercial RAM tester I had used to be able to push the RAM to its limits and over which was a great way to ensure reliability in high end systems but we're back in the 486 and Pentium MMX era...

author: daqq
author_rank: Super Contributor
timestamp: May 10, 2017, 06:09:12 am
content: It is possible, but given what speeds current memories work with and the requirements of the modules themselves, it would be very expensive to develop.The simple solution is to use a PC with a motherboard that supports your particular memory type and make a software solution that would stress the memory.

author: james_s
author_rank: Super Contributor
timestamp: May 10, 2017, 08:09:28 pm
content: I have an old DSI RAM tester, the thing is fantastic for working with vintage gear. Pop in a SIMM or DIMM and it tells you the capacity, tests the speed and then it can run a full test. I don't think mine will work for anything beyond the Pentium II generation but surely more modern machines exist.

author: David Hess
author_rank: Super Contributor
timestamp: May 11, 2017, 11:05:39 am
content: Quote from: CJay on May 09, 2017, 04:43:03 pmIt requires more than that. Besides timing, the supply voltages should be swept. Good floating gate memory programmers do this also to verify programming margin.As far as how to do this economically, a PC motherboard with one of the good memory test applications is probably the best way and I would deliberately run the memory at its lowest specified voltage and maybe 10% faster than its rated speed. Some motherboards support a +10% clock speed mode for burn in testing which would be ideal.

author: CJay
author_rank: Super Contributor
timestamp: May 11, 2017, 11:10:12 am
content: Quote from: David Hess on May 11, 2017, 11:05:39 amNowhere near as simple as it used to be, I can't imagine many aftermarket/'refurb' places going to that trouble unless it can be done programmatically?

author: David Hess
author_rank: Super Contributor
timestamp: May 11, 2017, 12:04:29 pm
content: Quote from: CJay on May 11, 2017, 11:10:12 amThe best automatic testers do all of this but the right PC motherboard when set to "burn in" mode and with the RAM supply voltage set to minimum will work. The slowest part of the test is waiting for the memory test to finish.