Question RAM Debacle

[grzlybear]

Hi all, I'll try to keep this short while giving some context.


A month ago, I installed a MSI B450 gaming pro carbon AC and a new Ryzen 7 3700x. As you may know, MSI really struggled to get these b450 boards working correctly with the new gen ryzen's, but (they claim) BIOS updates have remedied this for most people.

On every BIOS version, my PC would boot to post 1 out of every 20 tries with me re-flashing the board / resetting CMOS between each try. Not ideal.

I noticed that my RAM is not on the RAM list for use with this board. So I started investigating there.

Lets call my RAM sticks "A" and "B."

With A and B both in = CPU debug light (this is what usually happens.)

With A in and B out = CPU debug light

Moving B to A's slot, and leaving A out = fully boot to post, every single time.

Having B in the first slot and A in the second = fully boot to post, every single time.


I decided to run memtest86, as the above results would suggest that clearly something is wrong with stick A, since by itself or in the first slot the computer will not boot to post.

I ran memtest86 on B, and it came back with no errors. I tried booting into memtest86 with just A, but the CPU debug light comes on. So RAM A can't even boot into memtest86.

I have memtest running now with B in slot 1 and A in slot 2. If errors come back, can I safely assume that RAM A is indeed the culprit? I've read stories about RAM sticks doing weird things in memtest86 (e.g., passing individually but failing together, etc). Any thoughts about this or other ways I could test? I don't have spare RAM to swap in there unfortunately. I basically am trying to figure out if it is indeed one bad RAM stick or if there's something clearly wrong with this motherboard. Thanks in advance friends.

 

[Darkbreeze]

Were these memory modules purchased TOGETHER, in ONE set, or separately as individual memory modules?




Your memory is probably not in the correct slots.



Population rules for ALL dual channel motherboards, including yours, indicate that the memory should be installed in the second and fourth (Not 1st and 2nd) slots over from the CPU which are the A2 and B2 slots.

Start there. If they are not already in the second and fourth slots, with the fourth slot being the one closest to the edge of the motherboard, then move them there followed by doing a hard reset of the BIOS as follows.

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes, press the power button on the case for 30 seconds. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

If you had to remove the graphics card you can now reinstall it, but remember to reconnect your power cables if there were any attached to it as well as your display cable.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

In some cases it may be necessary when you go into the BIOS after a reset, to load the Optimal default or Default values and then save settings, to actually get the hardware tables to reset in the boot manager.

 

[grzlybear]

Were these memory modules purchased TOGETHER, in ONE set, or separately as individual memory modules?




Your memory is probably not in the correct slots.



Population rules for ALL dual channel motherboards, including yours, indicate that the memory should be installed in the second and fourth (Not 1st and 2nd) slots over from the CPU which are the A2 and B2 slots.

Start there. If they are not already in the second and fourth slots, with the fourth slot being the one closest to the edge of the motherboard, then move them there followed by doing a hard reset of the BIOS as follows.

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes, press the power button on the case for 30 seconds. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

If you had to remove the graphics card you can now reinstall it, but remember to reconnect your power cables if there were any attached to it as well as your display cable.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

In some cases it may be necessary when you go into the BIOS after a reset, to load the Optimal default or Default values and then save settings, to actually get the hardware tables to reset in the boot manager.

Thank you for the thoughtful reply. The RAM sticks were purchased as a pair, in one set. The RAM sticks have been installed correctly on the 2nd and 4th slots since I first put it together, so I don't think that's necessarily the case. Upon re-reading my original post I see I said "slot 1 and slot 2" .-- sorry about that. In my brain I was thinking of A2 and B2. The interchanging I discuss in the original post is all occurring between these two slots. I also have a bit of an update!

Having RAM "B" in 2nd slot and "A" over in the 4th slot, memtest86 found no errors. However, upon reboot, the computer would not post. It would post once I removed the suspected "bad" stick from the 4th slot like before.

I put the confirmed "good" stick (stick B) into the 4th slot by itself, to try and determine if the 4th DIMM slot was the problem all along. It booted fine, though. So I'm really not sure what it could be. I'd love to run memtest on JUST the suspected bad stick (stick A) but it can't even boot into memtest86 on its own.

At this point I'm thinking of just buying new RAM (which would answer a lot of questions) / running memtest86 for several hours overnight.. but I'd appreciate any additional thoughts.

 

[Darkbreeze]

RAM has a lifetime warranty. Pretty much, all of it, regardless of brand. For sure all of the major brands do. What model is your kit?

I'd RMA the memory as to me, it's almost certain that you have a bad memory module regardless that it passed Memtest. I've seen literally fifty or more cases where a memory configuration could pass Memtest and there was still a bad stick. Memtest tests for specific faults, but there are conditions outside the parameters that Memtest tests for that could bad, and additionally, there are only a limited number of tests that the free version of Memtest allows you to use. The paid version has additional tests so clearly there are things that CAN be wrong which are not tested for using the free version.

That is why we generally recommend running Memtest, all 11 free tests, for four passes, followed by running either a custom Prime95 configuration intended to specifically target known memory issues or at least a full range testing using the Blend mode option for several hours and then running the Windows memory diagnostic extended test. All of these tests test for entirely different faults or instabilities, so the fact that a set of sticks or a specific one is able to pass Memtest does not in ANY way mean there can't still be a problem with one of the modules OR that one of the modules might have trouble running with the other stick under certain conditions. Or at all for that matter. Even if they DID come together in a set.

I've seen plenty of tested memory kits where one module simply wouldn't work with the rest of the DIMMs in the kit, but worked fine by itself, as did the others together.

Buying a new kit is certainly an option, but I'd still RMA your current kit regardless because if it's faulty, it should be replaced at the expense of the manufacturer AND don't let them try to replace just one stick or else you're back to the original sin of not using mixed memory, only memory that was tested and determined to be compatible, together. They WILL try to do that though, because they'd rather limit their culpability to the loss of only one stick rather than having to replace a whole kit. You bought a kit, and if there is a bad stick, a brand new complete, matched and tested kit is what should be returned to you under the conditions of the warranty.