Issues after adding RAM to my PC

[Collapse7352]

Hello everyone! I am having some issues running my RAM at fast speeds after I added more. First of all my specs are:
MB - MSI MPG Z690 CARBON WIFI (MS-7D30)
CPU - Intel i9 12900K
PSU - 750W
RAM (Before Upgrade) - 2x16 Kingston KF560C40BBK2
I have updated my BIOS to the latest version from 2024-08-02.

Edit : Forgot to mention, I'm running Linux Manjaro in case it matters.

 

Base clock for the ram is 4800 MT/s. It runs fine on XMP at 6000 MT/s

 

I purchased a 2x32 kit of the same model KF560C40BBK2 with the intent to add it to the 2 empty ram slots. Whenever I put all 4 of the sticks in the slots, the memory refuses to run at anything higher than 4000 MT/s, which is lower than the base speed of the mode. If I put just 2 sticks from the different pairs (16+32), the memory runs at base speed and at the lowest XMP profile (still 4800 MT/s, but faster timings).

 

I can't find anything in the mobo manual telling me that it can't run all 4 slots at the proper speeds, but there is a chance that I am missing something. I understand that the issue is likely caused by the fact that I am using 2 separate kits of 2, instead of a single kit of 4. It's also worth mentioning the the 2 kits are assembled in different places (one in China and one in Taiwan).

 

Is there anything I can do to make it work? Can I and should I try manually overclocking the memory as an unexperienced overclocker? If I order another 2x32 kit from the same place, can I be sure that it will match with the other one? What would be the best course of action in my situation?

[RONOTHAN##]

21 minutes ago, Collapse7352 said:

I put all 4 of the sticks in the slots

Well there's your probelm. 4 DIMMs of DDR5 is known to be finnicky at best and struggle to work at higher speeds. Honestly it's a miracle that it even boots with this config, let alone work at 6000MT/s. 

 

There's also the issue that this is a triple rank memory setup. Without going into too much detail about it, more memory ranks has a performance per clock advantage (there is diminishing returns though). 16GB sticks are (almost) always single rank on DDR5, while 32GB sticks are (at the moment) always dual rank, so having a single rank and a dual rank stick on each channel results in triple rank to the memory controller. Dual rank sticks on 12th gen at best runs at ~6000MT/s (some slightly higher, some slightly lower), and quad rank is closer to 4400MT/s being the absolute max. Triple rank is usually closer to quad rank than dual rank for max memory speed, so this will likely be 4400-4800 as the max speed you can hope for with a bit of manual tuning. 

 

32 minutes ago, Collapse7352 said:

If I order another 2x32 kit from the same place, can I be sure that it will match with the other one?

As eluded to above, that would likely be just as bad. That would result in quad rank, which getting anything higher than 4400MT/s to work is next to impossible a lot of the time. 

 

32 minutes ago, Collapse7352 said:

What would be the best course of action in my situation?

Depends on how much RAM you really need. If 64GB would do you fine, just run the new kit as is. If you really do need 96GB, return this kit and get one of the 2x48GB kits and run that instead (preferably one of the 6000 CL30 or 6400 CL32 kits for better compatibility and much better performance compared to the cheaper 5600 CL40 and 6000 CL36-44-44 kits)

[Collapse7352]

6 minutes ago, RONOTHAN## said:

4 DIMMs of DDR5 is known to be finnicky at best and struggle to work at higher speeds

Interesting. I guess it didn't come to my mind that this could be an issue, especially since they sell kits of 4 sticks of DDR5.

Anyways, thanks for your time and help, I really appreciate it!

[PDifolco]

48 minutes ago, Collapse7352 said:

Hello everyone! I am having some issues running my RAM at fast speeds after I added more. First of all my specs are:
MB - MSI MPG Z690 CARBON WIFI (MS-7D30)
CPU - Intel i9 12900K
PSU - 750W
RAM (Before Upgrade) - 2x16 Kingston KF560C40BBK2
I have updated my BIOS to the latest version from 2024-08-02.

Edit : Forgot to mention, I'm running Linux Manjaro in case it matters.

 

Base clock for the ram is 4800 MT/s. It runs fine on XMP at 6000 MT/s

 

I purchased a 2x32 kit of the same model KF560C40BBK2 with the intent to add it to the 2 empty ram slots. Whenever I put all 4 of the sticks in the slots, the memory refuses to run at anything higher than 4000 MT/s, which is lower than the base speed of the mode. If I put just 2 sticks from the different pairs (16+32), the memory runs at base speed and at the lowest XMP profile (still 4800 MT/s, but faster timings).

 

I can't find anything in the mobo manual telling me that it can't run all 4 slots at the proper speeds, but there is a chance that I am missing something. I understand that the issue is likely caused by the fact that I am using 2 separate kits of 2, instead of a single kit of 4. It's also worth mentioning the the 2 kits are assembled in different places (one in China and one in Taiwan).

 

Is there anything I can do to make it work? Can I and should I try manually overclocking the memory as an unexperienced overclocker? If I order another 2x32 kit from the same place, can I be sure that it will match with the other one? What would be the best course of action in my situation?

Try running only the 2x32GB sticks, 64GB is usually more than enough for most tasks

[Collapse7352]

1 minute ago, PDifolco said:

Try running only the 2x32GB sticks, 64GB is usually more than enough for most tasks

Yes, that's what I will be doing for now. I am hosting a windows VM and my machine was struggling from time to time with the 32 gigs, since I am running stuff on both the host and the VM at the same time. Wanted to be sure with 96 gigs, but 64 should feel better too.

[Tetras]

34 minutes ago, Collapse7352 said:

Interesting. I guess it didn't come to my mind that this could be an issue, especially since they sell kits of 4 sticks of DDR5.

Anyways, thanks for your time and help, I really appreciate it!

AMD do at least publish how they much derate their memory controller on the spec pages of their CPUs, but even though Intel have confirmed this publicly, Intel Ark just says "Up to".

[RONOTHAN##]

16 minutes ago, Tetras said:

AMD do at least publish how they much derate their memory controller on the spec pages of their CPUs, but even though Intel have confirmed this publicly, Intel Ark just says "Up to".

Intel has the same page, it's just a little more hidden. On a 2DPC board, 4400 for two DIMMs, 4000 for two single rank DIMMs, and 3600 for 2 dual rank DIMMs. The rated 4800 is only for 1DPC boards. 

[Somerandomtechyboi]

1 hour ago, RONOTHAN## said:

Dual rank sticks on 12th gen at best runs at ~6000MT/s (some slightly higher, some slightly lower), and quad rank is closer to 4400MT/s being the absolute max. Triple rank is usually closer to quad rank than dual rank for max memory speed, so this will likely be 4400-4800 as the max speed you can hope for with a bit of manual tuning. 

and i thought noone tested cursed tri rank

 

is there a possibility of mix match though? afaik 5600c40 is just crappy samsungs and lower is crappier microns with low cl 6000+ bins (6000c30/6400c32 and up) being hynix a die

 

havent really looked at ddr5 that much ics wise cause it seems like nothing has topped a die yet for 16gbit nor got anywhere near it