Question Why aren’t my ram kits working together?

[GBDev]

Hello,

In my PC i had the Corsair vengeance CL40 DDR5 32GB 2x16GB 5600MHz and i wanted to expand it 64GB so i purchased the same kit except its at a lower speed 5200MHz. When checking online i saw they’d be compatible with no issues when pairing them with a i7-14700K and the Rog Strix Gaming-F Wifi II motherboard. So i placed in my new kit but the orange LED turned on. so here is what I tried to do to fix it but still isn’t working:

1. I tried adding only one of the sticks from the 5200 kit and it didn’t work

2. I tried removing the old kit and only adding only the new one and it didn’t work

3. I removed the new kit and went into the BIOS to manually adjust the speed to 5000MHz a common speed between both kits. Then added the new kit and it didn’t work

4. I tried clearing the CMOS then installing the new kit then running the pc to make sure it works then installing back the old kit and it still didn’t work.

5. I tried clearing the CMOS again and putting in the ram sticks from the new kit then the old kit one ram stick at a time and checking with each stick whether it works or not and it stops working when I enter the different speed ram sticks

I’m genuinely not understanding what the issue could be and bad news is i’m unable to return it or switch it out

EDIT: I forgot to mention that both kits never ran at their full speed and always ran at 4800MHz and in the Ai Tweaker section it was set to auto and i even tried to manually set it to 4800 but still no luck both kits won’t work together

 

[USAFRet]

Why?

Mixing different RAM sticks is always a crapshoot.
It is sold in sets for a reason...those particular sticks have been tested to work together.

You are very much not the only one to see incompatibilities, between what one would think as "identical".

 

[GBDev]

Why?

Mixing different RAM sticks is always a crapshoot.
It is sold in sets for a reason...those particular sticks have been tested to work together.

You are very much not the only one to see incompatibilities, between what one would think as "identical".

I didn’t notice it would cause any issues at all. When i checked even on pcpartpicker it said everything would work fine.

So is there a solution to this that i can eventually get to or is it never gonna work?

 

[USAFRet]

So is there a solution to this that i can eventually get to or is it never gonna work?

The "solution" would be to sell/return what you have, and buy a kit of exactly what you need.

Sometimes playing with the timings (reducing everything to the lowest value) can work, but often not.

Buy a set of 2x 32GB.


I recently tried similar.
2x 16GB. Worked fine.

Wanted to add 2x 32GB.
Seemed to work fine, initially.
Then, after a few minutes. ethernet cut out.

Swapping sticks, slots, changing timings....any combination of all 4 would result in the same issue.
Either pair worked fine on their own.

 

[GBDev]

The "solution" would be to sell/return what you have, and buy a kit of exactly what you need.

Sometimes playing with the timings (reducing everything to the lowest value) can work, but often not.

Buy a set of 2x 32GB.


I recently tried similar.
2x 16GB. Worked fine.

Wanted to add 2x 32GB.
Seemed to work fine, initially.
Then, after a few minutes. ethernet cut out.

Swapping sticks, slots, changing timings....any combination of all 4 would result in the same issue.
Either pair worked fine on their own.

I Understand, thank you for your time and help.

 

[geofelt]

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
Ram must be matched for proper operation.

You may get things to work if you specify the settings yourself in the bios.
XMP from two different kits may differ so don't bother with xmp.
On a working pair, set the speed, cas and timings yourself.
Set the voltage a bit higher than what is on the sticks.
Verify functionality by
running memtest86+
It boots from a usb stick and does not use windows.
You can download it here:

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

memtest.org

If you can run a full pass with NO errors, your ram should be ok.
Then add in the other kit and test.
If no joy, increase the ram voltage another notch and repeat.

 

[GBDev]

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
Ram must be matched for proper operation.

You may get things to work if you specify the settings yourself in the bios.
XMP from two different kits may differ so don't bother with xmp.
On a working pair, set the speed, cas and timings yourself.
Set the voltage a bit higher than what is on the sticks.
Verify functionality by
running memtest86+
It boots from a usb stick and does not use windows.
You can download it here:

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

memtest.org

If you can run a full pass with NO errors, your ram should be ok.
Then add in the other kit and test.
If no joy, increase the ram voltage another notch and repeat.

Thank you for the information but i managed to return the kit and i’ll be purchasing another of the same exact kit i already have. Also wanted to mention they both had the same timings 40-40-40-70 and both running at 4800Mhz at 1.25V

 

[geofelt]

You missed the issue.
Two separate kits will not be matched.

If you want 64gb, without issues, buy a 2 x 32gb kit and keep the old kit as a spare.

 

[USAFRet]

but i managed to return the kit and i’ll be purchasing another of the same exact kit i already have.

Even that might not work.

Unless it comes in the same kit....crapshoot.

 

[GBDev]

You missed the issue.
Two separate kits will not be matched.

If you want 64gb, without issues, buy a 2 x 32gb kit and keep the old kit as a spare.

I don’t understand, then what’s the point of having 4 DIMM slots if i’m only gonna be allowed to use 2 and i have to use the same kit?

 

[USAFRet]

I don’t understand, then what’s the point of having 4 DIMM slots if i’m only gonna be allowed to use 2 and i have to use the same kit?

You buy a set of 4.
Not 2 different sets of 2 each.

And almost always, 2x works better than 4x, of the same total capacity.
ex:
2x 32GB (64GB) is generally better than 4x 16GB (64GB).

 

[GBDev]

In that case, I'm just gonna stick to 32 GB. Thanks to everyone for contributing to this discussion and helping me be more knowledgeable about this issue

 

[USAFRet]

In that case, I'm just gonna stick to 32 GB. Thanks to everyone for contributing to this discussion and helping me be more knowledgeable about this issue

And in my case, I needed to move up from 32GB.

The 32+64 (96GB) did not work.
So it remains at 64GB, and I sold off the 2x 16GB (32GB) set.

Large CAD models made the prev 32GB cry, and some are bumping up against the 64GB ceiling.

The system I'm in the process of assembling will be 96GB (2x 48GB).

 

[GBDev]

Neat! Good luck with your build