Mixed RAM speeds

[Phosfr]

Hello guys,

I ventured into the PC world around a year ago and built my first gaming PC, back then I only put in 1 stick of 8gb RAM at 2666mhz.

Now a few months after I bought another stick of 8gb RAM but this was 2100mhz (I didn't really know what I was doing)

Now I've just bought another 16gb of Corsair RAM at 3000mhz.

I understand that all my RAM will run at the speed of the slowest stick, so here's my question, what would be better, 32gb at 2100mhz or 24gb at 2666mhz?

 

[feelinfroggy777]

What are you using the system for? For most applications, you wont need more than 16gb of RAM. Having more RAM does not increase the speed of your system, but any RAM not used by an application will just sit idle. If this is a gaming rig, you only need 16gb.

As far as RAM speed, some CPUs scale better to higher speed RAM. If you have a Ryzen CPU, then faster RAM will scale much better than an Intel CPU.

 

[thx1138v2]

I understand that all my RAM will run at the speed of the slowest stick, so here's my question, what would be better, 32gb at 2100mhz or 24gb at 2666mhz?

That's only if they work together at all. You'll probably need to first determine which sticks will work together at all and which won't that may answer your question for you.

 

[Phosfr]

Im using it for gaming, so I should take the old slower ram out and just use the 16gb of Corsair I've just bought?

Also, I've taken the old ram out, and just put the Corsair in, and in the bios it says the speed is 2133mhz? It should say 3000mhz right?

 

[feelinfroggy777]

Im using it for gaming, so I should take the old slower ram out and just use the 16gb of Corsair I've just bought?

Also, I've taken the old ram out, and just put the Corsair in, and in the bios it says the speed is 2133mhz? It should say 3000mhz right?

Yes, just use the 16gb Corsiar kit and sell the rest of the RAM. What motherboard do you have? You will need to set the XMP profile for the RAM to run at 3000mhz.

 

[Phosfr]

Asus z270 motherboard, xmp is set to 3000 bit I don't think it's doing anything

https://photos.app.goo.gl/KsL3wwY2kWWgfwAHA

 

[Dugimodo]

that screenshot contradicts itelf twice, probably just the BIOS reporting the default speed in one place and the actual speed elsewhere.
Try running CPU-Z and check what it tells you the RAM speed is.

 

[Phosfr]

That's what I'm saying, it shouldn't be saying 2133 at all!

Cpu-z says 1544.7mhz which is 3080 right?

https://photos.app.goo.gl/UEx7U51AbZN2gBvHA

 

[feelinfroggy777]

Yes, it is working with XMP. XMP is just a one button overclock for RAM. With XMP running, your RAM It is clocked at 3091mhz. DDR stands for double data rate. CPU-z is showing 1544 and that number should be doubled for the double data rate. Your bios is showing the RAM clocked at 3091. It is running just fine and as it should. You can also use Intel XTU to verify speeds, but your system is fine.

 

[Dugimodo]

What I think the confusion is, the BIOS status is just reading the Name of the RAM that's located in each slot and displaying it and that Name includes the default (non XMP) speed as part of the text. In other words the status is not reporting the speed of the RAM, just tellling you what is in each slot.

I would put money on that status staying the same regardless of how you clock the RAM, it's just an Identifier.

 

[Phosfr]

Thanks for the help guys