• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

DDR3 RAM Mystery....

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


New Member
Jul 8, 2019
Hello all,
I'm new to the community, but have been dabbling with computer hardware for the entirety of my life. In the last year, I picked up the perfect desktop for tinkering, and have been doing just that. It's an older machine, with a questionable past, but the specs are as follows:

Motherboard: EVGA X58 Classified

CPU: Xeon W3690 (3.47ghz stock, currently OCed to 4.2ghz stable), air cooled with Cooler Master Hyper 212 Black Edition cooler

GPU: Nvidia RTX 2080

RAM: 40gb Team Elite Plus 1333, 8gb x4 and 4gb x 2 DIMMs (OCed to 1403mhz at 1.55v)

OS: Windows 10 Pro

Power supply: Ultra X4, 1050W

Case: Cooler Master HAF 952

On to my issue: This PC came to me without the Xeon chip, the 2080, and the two 4gb sticks of RAM. Those components I added myself. The motherboard also required a bit of physical modification for the processor to interface with it, in the form of soldering jumper pads on the board in two locations (done with a professional soldering station in a shop I worked for). I ordered the 4gb RAM sticks after installing the Xeon, as the system only ever reported 16gb of RAM from the existing 4 sticks, even with the old i7 920 CPU installed. The goal was a total of 24gb, which with those sticks installed, the PC recognized that quantity.

Fast forward to this past weekend, and I decided to do some overclocking with the goal being an improvement on performace for CAD and 3D modeling work. While slowly increasing values and trying different things to stabilize my overclock, I happened to notice in CPU-Z that the reported amount of RAM was 40gb. More oddly, when I looked at the system about page in Windows settings, it reported only 8gb at that time. Thinking I knocked one or more sticks loose while tinkering inside the case, I shutdown, pulled all the RAM and reinserted it, at that time finding that the majority of the sticks were 8gb and not 4gb as I had thought. When reseated and the pc rebooted, the system then reported 32gb or available RAM. Trying again, following the motherboard manual's slot ordering scheme as a guide, I reordered the sticks in hopes that it would recognize all 40gb of RAM. After several attempts, the during which the amount of ram present varied from 16 to 28gb, I could never get all of it recognizable to Windows, nor could I get it back to 32gb as it once identified.

I was finally able to get the RAM capacity to stay stable back at 24gb and left it alone at that point. In doing some reading, the W3690 is listed as only supporting 24gb of RAM anyway, though I hear some people have gotten it to work with more. Oddly, I only get 24gb recognized with all 6 sticks installed. Trying 3x 8gb sticks yeilds only 16gb of RAM, as does having all four 8gb stick installed. This doesn't seem to be a symptom of bad overclocking, as the amount of RAM has always reported at 24gb or less even when set to stock settings.

So questions I have are:

- Being triple channel, is the mixing of 4 and 8 gb DIMMs causing issues with the memory controller? I had thought that the mismatch would cause the memory controller to operate in dual channel mode, and everything would be fine.

- Could this be a processor issue? The memory controller is built into the processor, I wonder if it has a problem? I'm also considering a lateral upgrade to a X5690 instead that will host way more memory, including ECC RAM. Is that an OK idea?

- is there a setting somewhere in the Bios I'm not seeing or setting right? I've tried everything in an think of, but I defer to the experts.

- If CPU-Z sees the full RAM amount, despite what Windows thinks, is the total quantity of RAM allocatable to other software, or am I limited to what Windows can see?

- Any other thoughts?

Sorry for being so long winded, however I felt the more detail I give, the better understand you all might have. Thanks for any and all help you can give.

Last edited by a moderator:
Windows will see what you (it) can utilize. It doesn't care about anything else.

If you need more memory, than a chip that supports more memory is a definite plus.

My experiences with mismatched RAM only taught me that the motherboard will drop all speeds and timings to the slowest stick.
I see this marked as solved (odd that this user has the ability but other users cant on their own threads)... what was the resolution?
Windows will see what you (it) can utilize. It doesn't care about anything else.

If you need more memory, than a chip that supports more memory is a definite plus.

My experiences with mismatched RAM only taught me that the motherboard will drop all speeds and timings to the slowest stick.
That's what I thought... The RAM speed and timing is less of a concern however, as they're all the same at 1333 and 9, 9, 9, 24...

I don't necessarily need more RAM, it helps with rendering though, but more than anything I want what I have now to work like it should. I still. Don't understand how or why it would read less RAM than is installed no matter how may sticks are in the machine. The exception of course is when I have one stick in, then it reads the amount correctly

This platform had problems with RAM after longer work or when memory was often replaced in slots. It also needed higher IMC voltage for higher capacity RAM setups (matter of motherboard and CPU). It looks like BIOS can't see some capacity or it sees full capacity but in Windows usable is less than expected.

I recommend cleaning memory contacts with some kind of alcohol or anything which is designed to clean electronics (personally I'm using 95% alc for that but in many countries it's not available in stores). Use condensed air in memory slots or can also try to clean them but it's not easy and can damage slots if done wrong.

Also when you use more memory modules (4+) then you may have to set higher QPI/VTT voltage.

Officially X58 was designed to support 24GB RAM max so every CPU and motherboard specification which wasn't updated (and most were not updated) will tell you that this platform doesn't support more RAM. 48GB option appeared long after premiere and not all motherboards could support that (mostly because manufacturers didn't care to release BIOS).
Sorry for the delay in replies, it's been a crazy week at work...

Womack, thanks for the advice. I definitely will give cleaning memory slots a try, thats something that I should have done a long time ago... This PC was actually salvaged from a fire at a friend's apartment, though it did not seem to have suffered any heat damage, just a little bit of smoke and maybe some light liquid damage. The machine was put away in storage following the fire, and was not touched until it was given to me more than a year later. The smoke damage was very minor, and required very little cleaning when I first tore down. The liquid damage seemed to be confined to the top of the optical drives, which I have no need for anyway. Everything else was pristine, so my cleanup was minor. As the memory slots were filled it didn't occur to me at that time to clean them.

As far as cleaning agents, I can get and do use 91% alcohol, but I love a product called De-Ox It, designed for electrical contact cleaning. I've used it on Pro Audio gear for years along with its companion, Caiglube MCL, for cleaning and lubricating the faders, pots, contacts on audio consoles and power amps. I haven't tried it on PC components before, but I don't see why it wouldn't work....

In my travels this week I picked up two additional 8gb sticks of RAM to see what might happen if all the sticks were the same capacity. Now I have 32gb of RAM recognized by the system, and CPU-Z sees all 48gb. I have manually set the ram timing and speed, as well as boosting the VTT voltage and memory voltage. Any advice on where the redline is for either is? I raised both considably and ran some benches with CPU-Z as well as one in Tomb Raider and got considerably better results, but the voltage values scare me a bit, so I keep them set to auto for daily use as it's stable that way.

I also have a new theory about why all the RAM is not recognized in Windows: As the W3690 is designed for a maximum 24gb of RAM, I'm wondering if it's only really able to utilize 4gb DIMMs and doesn't know how to handle the 8gb DIMMs I have in it. That may explain the wierd values I'm seeing, if it is trying to allocate 4 of the 8gb from each stick. To test this theory, I went ahead and ordered a X5690 this morning, and accidentally ordered a X5687 as well earlier in the week as well. Both are designed for 250gb of RAM and should recognize up to 32gb per stick.

If it works, might consider swapping the RAM out for a matched set of ECC DIMMs.

Memory weirdness or not, when it comes to CAD work, my overclock is downright impressive. At work, I draft on an i7-8700K at 4.5ghz, 64gb RAM, and a Quadro P4000. The job I'm currently working on is very taxing to the system, comparatively, I loaded up one of the heavier files on my home system, and it handles it with ease. I'm guessing that's mostly the RTX 2080 though.

Update: The X5690 arrived today, and much to my disappointment, no change in my memory issue, and the multiplier is also locked...

Some more troubleshooting though: after I bit of trial and error, I have come to the conclusion that memory slots 1 and 2 are no longer working properly. And RAM placed in those slots goes unrecognized by Windows and the bios as it turns out, though it's still visible in CPU-Z, so I don't really know what to make of it. I tried swapping around DIMMs in search of a bad one, tried each individually, and nothing on slots 1 and 2. Installing. DIMM into one or two and trying to boot yields no post. Installing 4 sticks into 3-6 yields 32gb of RAM no matter which of the 6 sticks install.

I am running the latest bios firmware, have checked that I have no bent pins in the cpu socket, have tried loosening and tightenijg the CPU cooler all to no avail. It seems that this board has had a myriad of issues of this type, so I guess it's time to swap it out for another. Was thinking about the Asus Rampage III extreme, but they are awfully pricy.