Question Can you mix ram?

UKTone

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Feb 24, 2015
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The ram i have in my signature can't use the thing in the bios (forget what it's called), the ram i bought about a month ago is compatible with the technology, but was wondering if i can have 64 gbs with this board and if i can mix the two rams. And if i can, can i use the technology on just the 32 gbs that is compatible?
 
You may be thinking of XMP?

What motherboard are you talking about? Please post full system specs.

Like geofelt said, a motherboard will either have DDR4 or DDR5 ram. You physically cannot put DDR4 RAM into a DDR5 slot and vice-versa. So they cannot work together.
 
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Yes, xmp is what i'm talking about, thank you. And oh i'm not mixing ddr4 and ddr5 ram, i'm trying to mix different speeds of ram https://valid.x86.fr/ez1fek has the ram that is currently in my pc which is this one based on the model number https://www.corsair.com/us/en/p/mem...00mhz-c36-memory-kit-black-cmk32gx5m2d6000c36 and this is what i bought, which is compatible with my motherboard's xmp feature CMT32GX5M2X6200C36 https://www.corsair.com/us/en/p/mem...mhz-c36-memory-kit-a-black-cmt32gx5m2x6200c36

The motherboard i'm using is Asus PRIME Z790-A WIFI https://www.asus.com/us/motherboards-components/motherboards/prime/prime-z790-a-wifi/ and i used this to find the ram that is compatible https://www.asus.com/motherboards-c...pdesk_qvl_memory?model2Name=PRIME-Z790-A-WIFI (you can copy and paste the ram model number in the search to confirm)

And lastly, was wondering if i can use xmp with just the 32 in their channel if using all 64gbs? And does the motherboard support 64gbs? Any problems with using 64gbs of ram? Especially if they are different speeds? Normally, i would have bought all the same, but never knew if they had to be all the same. Do they have to be the same for their channel?

Think this is a more complete question, sorry for not writing out details, but anything else should be in the validation if i missed anything you guys would need, the only thing not accurate in the validation right now is that i'm using a 4070 Super instead of the 3050.

Thank you.

Edit: The ram under Old in my signature is not in the equation at all. I see how that could've gotten confused on my first post.
 
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Yes, xmp is what i'm talking about, thank you. And oh i'm not mixing ddr4 and ddr5 ram, i'm trying to mix different speeds of ram https://valid.x86.fr/ez1fek has the ram that is currently in my pc which is this one based on the model number https://www.corsair.com/us/en/p/mem...00mhz-c36-memory-kit-black-cmk32gx5m2d6000c36 and this is what i bought, which is compatible with my motherboard's xmp feature CMT32GX5M2X6200C36 https://www.corsair.com/us/en/p/mem...mhz-c36-memory-kit-a-black-cmt32gx5m2x6200c36

The motherboard i'm using is Asus PRIME Z790-A WIFI https://www.asus.com/us/motherboards-components/motherboards/prime/prime-z790-a-wifi/ and i used this to find the ram that is compatible https://www.asus.com/motherboards-c...pdesk_qvl_memory?model2Name=PRIME-Z790-A-WIFI (you can copy and paste the ram model number in the search to confirm)

And lastly, was wondering if i can use xmp with just the 32 in their channel if using all 64gbs? And does the motherboard support 64gbs? Any problems with using 64gbs of ram? Especially if they are different speeds? Normally, i would have bought all the same, but never knew if they had to be all the same. Do they have to be the same for their channel?

Think this is a more complete question, sorry for not writing out details, but anything else should be in the validation if i missed anything you guys would need, the only thing not accurate in the validation right now is that i'm using a 4070 Super instead of the 3050.

Thank you.

Edit: The ram under Old in my signature is not in the equation at all. I see how that could've gotten confused on my first post.
You might want to update the bios first.

Mixing ram is iffy.
 
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When you mix two kits they can experience problems. Your RAM may be unstable or the computer may even refuse to boot.
Or, everything works without a problem. It's a lottery and for best performance i suggest you sell your kit or both of them, and instead buy a new kit that has the specs you want. Preferably with latency no higher than CL32. Unless gaming isn't a priority.

Your new kit is faster, so if you want 6200, sell the older one.
If you want 64Gb, sell both and buy a 2x32Gb kit but i should warn you that it will be either slower or very expensive. If you just want 64 for the hell of it, you're getting it at a penalty so stick with 32Gb if that's enough for your work.


You cannot enable XMP for individual sticks of RAM, whether they're a single kit or mixed kits. XMP is enabled for the whole thing.

Enabling XMP is how you get the RAM to work at it's highest stated speed, in your case 6200 for one kit and 6000 for the other. Since they are mixed, you could not hit 6200 no matter what because one kit cannot run that fast.

If you could even get 6000. Asus documentation isn't clear but typically when you populate all four DIMM slots, the maximum speed drops. This is because the memory controller has more RAM to manage.
For this reason kits of two sticks of RAM are recommended. They support dual channel at highest speed.

The larger the individual "stick", the slower it runs. Or if it's fast it's also mega expensive.
2x16 Gb 6000 CL30 is the sweet spot right now. CL28 even better if you find any. 6400 CL 32 is also good.


Hope this helps. If you have more questions, please ask.
 
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I'm going to go against the grain here. I have mixed RAM in my build and it runs just fine - caveat - only at DDR4 2133 speeds. The only reason I run mixed ram is because I had some old DDR4 kicking around and it seemed a waste not to use it.

Buying from new? Buy matched RAM.
 
I'm going to go against the grain here. I have mixed RAM in my build and it runs just fine - caveat - only at DDR4 2133 speeds. The only reason I run mixed ram is because I had some old DDR4 kicking around and it seemed a waste not to use it.

Buying from new? Buy matched RAM.
Sometimes it works, sometimes it fails.

I had 2x 16GB DDR4, Corsair Vengeance LPX.
Add in 2x 32GB of the same....

Total, 96GB, right?
Nope.

It booted up just fine, and appeared to work.
After about 5 mins, problems started. Primarily, ethernet.

Each pair worked fine on its own. In any slot combination.
All 4 together, no.

Currently running n just the new 2x 32GB.
 
Sometimes it works, sometimes it fails.

I had 2x 16GB DDR4, Corsair Vengeance LPX.
Add in 2x 32GB of the same....

Total, 96GB, right?
Nope.

It booted up just fine, and appeared to work.
After about 5 mins, problems started. Primarily, ethernet.

Each pair worked fine on its own. In any slot combination.
All 4 together, no.

Currently running n just the new 2x 32GB.
Yeah, I agree your mileage will vary. What I did do was to make sure both memory channels were populated equally. Maybe that was the secret sauce?
 
I'm going to go against the grain here. I have mixed RAM in my build and it runs just fine - caveat - only at DDR4 2133 speeds. The only reason I run mixed ram is because I had some old DDR4 kicking around and it seemed a waste not to use it.

Buying from new? Buy matched RAM.
Lower speeds seem a bit more tolerant of a mix.

I also run a mix works fine.

So a mix becomes yes/no/maybe.
 
I'm going to go against the grain here. I have mixed RAM in my build and it runs just fine - caveat - only at DDR4 2133 speeds. The only reason I run mixed ram is because I had some old DDR4 kicking around and it seemed a waste not to use it.

Buying from new? Buy matched RAM.

That it only runs at 2133 is a pretty big caveat! Not quite "Our American Cousin was terrific performance despite that one incident" but still a pretty big but!
 
I've mixed RAM plenty of times and I have a good history of getting it to work, especially after some tinkering. However, I wouldn't try mixing RAM in a situation in which you're *counting* on it to work, such as very tight schedule or budget.
 
I'm going to go against the grain here. I have mixed RAM in my build and it runs just fine - caveat - only at DDR4 2133 speeds. The only reason I run mixed ram is because I had some old DDR4 kicking around and it seemed a waste not to use it.

Buying from new? Buy matched RAM.
If your running 2133 memory with the processor then your performance is gimped, 3200/3600 is the sweet spot for those processors.

Old DDR2 was no big deal at all pretty much just add another GB and go, DDR3 was fairly forgiving as long as you weren't trying to mix low and high density, DDR4 got a lot more picky, the DDR5 is even worse than that.
 
If your running 2133 memory with the processor then your performance is gimped, 3200/3600 is the sweet spot for those processors.

Old DDR2 was no big deal at all pretty much just add another GB and go, DDR3 was fairly forgiving as long as you weren't trying to mix low and high density, DDR4 got a lot more picky, the DDR5 is even worse than that.
Nah, the RAM runs in dual channel mode and despite the slow speed that's enough bandwidth for a single CCD CPU. There's no difference in UX and outside of memory benchmarks you would never know you were running slower RAM.

My build is far more GPU bound than it is held back by RAM.
 
Yeah, I agree your mileage will vary. What I did do was to make sure both memory channels were populated equally. Maybe that was the secret sauce?
There's no secret sauce, it's a lottery. You might win :)

Even completely identical kits will refuse to work together. Identical to the last letter of the partnumber.

The problem many don't seem to acknowledge is that a kit of two sticks is confirmed compatible ONLY as a kit of two sticks. That means no other sticks involved.
You double your memory by installing two such kits but they may instantly refuse to work in such conditions. Even though they're identical and confirmed compatible.

Because they're confirmed compatible as two sticks of RAM in the DIMM slots.


Using 4 sticks also has an impact on performance. This varies by motherboard. Some motherboards and kits don't lose much performance. Not enough to be noticeable.
Other motherboards may cut the rate in half.

Also, the CPU might complain about RAM specs but mostly the Intels don't care and Ryzens are neurotic whichever way the specs go.


That's why it's recommended to use a 2x kit because it's fastest and usually most stable. 4x kits are only a good option if trying to install large amounts of RAM such as 96Gb or above.

HOwever if you happen to have RAM lying around, you might as well take a shot. Even if the PC refuses to boot, it will not be damaged in any way.
And if everything works, you get extra memory.

But since extra memory will probably be wasted now that we're above 16Gb of RAM, i would take speed and stability over extra RAM.
For example if i have 32Gb and add another 8Gb, and it all works, i trade RAM performance for RAM i'm not likely to use because at least my system doesn't use more than 16Gb anyway.