Memory testing besides MemTest?

[Lmandrake]

I have a truly bizarre problem. I have two 1 GB sticks of DDR2 that will not allow me to boot into windows at any speed or setting but passes MemTest run overnight. Same board with other ram works fine and used to work with the problem RAM.

Even worse, the two sticks each allow me to boot into windows if used individually but do not allow booting if installed together in dual channel mode.
But it passes memtest in dual channel (???)

Anyway, I guess my problem ram doesn't like my board, but I would like to be more comfortable about it being good before selling it to someone. I always thought MEMTEST was the gold standard for ram testing. Are there other reliable test proggies I can use?

[TheSovereign]

u have to adjust your dual channel memory settings they are diffrent than single mode

[FlyingPenguin]

First off, make sure you're using MEMTEST86+ and not MEMTEST. I assume you just left off the 86+

Dual Channel is VERY fussy about timing. Most OEM manufacturers use VERY conservative timing on dual channel systems (HP in particular) for stability.

There are definitely situations where Windows will stress RAM in was where MEMTEST86+ won't.

I have a similar problem on my Opteron 148 LAN Party/Bench rig. Using each 1Gb stick it's fine, using them both in single channel is fine. Using them in dual channel causes Windows to crash about once every week or so (more often if I play a 3D game). This is high performance Corsair XMS memory which is notorious for requiring timing tweaking for specific mobos.

I sorta fixed it by searching Corsair's tech forum and finding recommended timing settings for XMS memory on that mobo. However it still crashes once in a while so I have up and configured it for single channel and it runs solid as a rock. Performance difference isn't all that big, and now it's solid as a rock.

Do a Google search for your memory model and your mobo model plus the phrase "recommended timing" and you'll probably find some recommendations.


ANOTHER POSSIBILITY is that it has nothing to do with the RAM. Your Northbridge chipset may be overheating. Make sure the HSF is fully seated. I've seen this pretty often. An overheating Northbridge acts just like bad memory.

Yet another possibility is that you need to upgrade your mobo's firmware.

[Err]

My Patriot Memory would cause windows crashes until I upped the voltage to the manufacturers specs.

[Key Keeper]

My asus mobo will not boot into windows if I run mem in A1 and A2. Only way it will boot is in B1 and B2 wich seems odd to me. Single channel it will boot any configuration but dual channel it is very picky.

[FlyingPenguin]

Key, I've seen mobos do that. The B slots are probably slightly closer to the Northbridge chip (at least the electrical path is) or maybe there's a slightly weaker capacitor on the A bus.

The truth is that Dual Channel is BARELY stable even on well engineered boards and very problematic on cheap mobos. It involves a lot of tricky timing by the memory controller otherwise you get timing issues.

You could have a stable system that's right on the hairy edge and all it takes is some power supply noise when the system is working the hardest to scramble the memory bus.

This is why some OEM systems have really slow memory timing - they're making up for cheap components. HP sets their timing so conservatively on AMD systems that they would be better off running it in single mode with aggressive timing - they'd get better performance but then couldn't brag about using dual channel.

[Lmandrake]

My BIOS does not seem to have separate settings for single or dual channel, so I don't think Sov's tip is applicable.

Here's the deal: Crucial Ballistix and Corsair XMS2 sticks work in dual channel at stock timings and manuf. specified voltages. OCZ platinum sticks work only in single channel. Slots do not seem to matter on this board.

In all cases my belief - not supported by much testing but a few anecdotal incidents - is that manual settings work better than auto.

FP, of course, knows more than any of the rest of us.... mile

Oh, I was using memtest+86 - I just didn't write that on my bootable cd when i burned it many years ago. I also found this - http://hcidesign.com/memtest/

Dunno how good it is, but its kind of handy to have something that runs in windows.

[FlyingPenguin]

Auto settings DO usually work best (for stability), but that's ONLY when buying manufacturer guaranteed compatible RAM and you're not overclocking.

For instance if you buy memory for a specific mobo or OEM system from Crucial using their online database you are guaranteed that it will work on the default auto timing settings. That's why I only buy Crucial for my clients. I don't need the hassles.

When you're using performance memory like Ballistix, OCZ or XMS then it's a different ball of wax. performance RAM most often works best with manual timing because it's not made for a specific mobo.

Most manufacturers are pretty good about this now - Corsair in particular. They do extensive testing of their XMS memory on different mobos and post the recommended timing on their forums. Also most of these manufacturers wil give you recommended timings if you email them with your mobo's model number.

You may have to really tweak that OCZ memory to make it work (fiddle with the timing and up the voltage). If you're lucky someone else has already done it and posted it on the web somewhere.

Ultimately though, there will always be some memory that just doesn't work with some mobos reliably and that may be the case here. Doesn't mean there's anything wrong with the memory, just that it's not compatible with that mobo.

Good luck.