Question Mismatched memory kits stable—but...

[Myronazz]

Hello,

I come with what I imagine is a typical question. I had a KLEVV DDR4-3200 2x8GB kit installed in my Ryzen 2400g system and I needed to upgrade it to 32GB. I bought another kit from that same brand and made the upgrade to 32GB.

I'm aware of the risks. I've personally taken them multiple times and had no issues. This time, there seems to be an issue though.

The system boots and is very stable. It doesn't crash and can handle stress tests. It's that, sometimes, when I boot it, it will shut itself down for one second and then restart to boot successfully. No BIOS warnings or anything though.

I'm currently running a memtest and aim for multiple passes. If it succeeds, I think I'll keep the kit.

Thoughts? Bare in mind that this is a server and I am sometimes physically away from it for months at a time.

System Specs:
Motherboard: ASUS Prime B350-Plus
RAM: 4x8GB KLEVV DDR4-3200 (clocked at 3000 right now)
CPU: Ryzen 5 2400g
PSU: Corsair RM-550x

GPU 1: GT 730
GPU 2: GT 610
GPU 3: Integrated Vega Graphics (I want to disable this one)

SSD 1: Corsair MP510 512GB (through M.2 to PCIe adapter)
SSD 2: Samsung Evo 128GB (boot drive)
HDDs: 5x Seagate 2.5" 320GB drives

OS: Ubuntu Server 21.04 LTS

 

[Roland Of Gilead]

Hey there,

Firstly, please list your full PC specs, including PSU.

Testing the mem is a good first call. It should show no errors. If there are any errors, then the ram is faulty.

How did you get a 28gb kit? That's not available for DDR4. Ideally, what you should have done was purchase a 2 x 16gb kit, and sell whatever you have to offset the cost.

What bios are you currently running on your mobo? You might need to update the bios to have ram compatibility with what you've purchased.

If I were you, I'd return the kit you bought and get a kit as mentioned above. If you are running a server, you'd want solid. stable ram, not fussing around to get it to work, when it may just start throwing up errors either way.

The shutting down you described sounds more like a PSU issue to me than a ram issue.

 

[Ralston18]

Server: update your post to include full system hardware specs and OS information?

What was the need or requirement driving the RAM increase from 16GB to 32GB?

Aside from the boot time shutdowns did performance improve?

All RAM kits should be matched sets. I would expect that a 4 x 8GB kit would be installed vs two 2 X 8GB kits which would not be truly matched.

Thus may not work at all, work perfectly, or work with problems such as you have decribed.

Look in the servers's logs: Any error codes, warnings, or even informational events being captured just before or at the time of the shutdowns?

Could be something else going on. Some problem or failed update. Some app trying to update, backup, phone home.

 

[Myronazz]

How did you get a 28gb kit? That's not available for DDR4. Ideally, what you should have done was purchase a 2 x 16gb kit, and sell whatever you have to offset the cost.

Sorry! I meant to say a 2x8GB kit. I bought another one of those to get a total of 32GB.

The shutting down you described sounds more like a PSU issue to me than a ram issue.

I doubt that. It only does it when it starts, and it's fine after that. And it's only sometimes.

Since that server is on most of the time, I can't recall if it was doing it before.

Testing the mem is a good first call. It should show no errors. If there are any errors, then the ram is faulty.

It passed a total of 3 times. I guess I'll let it pass a couple of more times.

Server: update your post to include full system hardware specs and OS information?

Sorry for not doing that in the first place. It's done now!

What was the need or requirement driving the RAM increase from 16GB to 32GB?

Building Android. It's something I've been wanting to get into for a long time. You need 32GB minimum to make builds.

In fact, I'm looking into getting a used Ryzen 7 3700X to gain a big performance boost for faster build times. It's a $60-80 upgrade from the prices I've seen so far.

 

[Roland Of Gilead]

Sorry! I meant to say a 2x8GB kit. I bought another one of those to get a total of 32GB.

Okay, fine. Yes, mixing ram can be problematic. Best option as mentioned is, a 2 x kit of 16gb. Rules out any potential issues. Sell what you have to offset the cost.

I doubt that. It only does it when it starts, and it's fine after that. And it's only sometimes.

Well, that's your choice. However, a PSU issue can be random or not, at start up or not, or simply whilst idling or at load. Your PSU is good quality, but it could be failing. How old is it? Given it's an RMx, it's prob only3 years or so? If it's not delivering enough power or clean power it may be causing your issue.

It passed a total of 3 times. I guess I'll let it pass a couple of more times.

Mem is fine. No errors after 4 passes indicates a certain amount of stability. What speed are they running at? Is xmp on?

Again, what Bios are you running on the mobo? You can use CPU-z to determine this easily.

 

[JayGau]

If it starts and runs for a few seconds on a black screen before restarting by itself and boots normally after that it would really sound like the motherboard is redoing some memory training time to time (especially if you see a yellow light on the board when it does it). In general they do that only once after you modify the ram settings but it's possible that yours is doing it again time to time. How hold is the cmos battery? In your BIOS, in the DRAM timing control, do you have an option called "memory context restore" and is it enabled or disabled?

By the way, someone recommended to use cpu-z to check your BIOS version but this software is not not available for Linux. The equivalent on Ubuntu is cpu-x.

 

[Myronazz]

I did more memory passes but it occasionally reboots before POSTing. I further clocked it down to 2800 MHz and it doesn't do it anymore. Unless I'm mistaken, the mismatched memory chips just can't work together perfectly on high speeds.

There might be a way around that but I'm willing to bet that this is just the cost of the risk I took.

Again, what Bios are you running on the mobo? You can use CPU-z to determine this easily.

My BIOS is version 6042 from 2022. There are several updates. Could the latest version from late 2024 help?

How hold is the cmos battery? In your BIOS, in the DRAM timing control, do you have an option called "memory context restore" and is it enabled or disabled?

It must be pretty old... at least from 2018. And I don't have a "restore memory context" option.