ram RAM Frequencies

[Syed Zaid Ahmed]

Can somebody guide me why people put more Hz of RAM as mentioned in processors datasheet, for example in the attached video Linus put 3200MHz of 64GB RAM with Core i9 9900K but according to datasheet of Core i9 9900K(https://ark.intel.com/content/www/us/en/ark/products/186605/intel-core-i9-9900k-processor-16m-cache-up-to-5-00-ghz.html)

it says 2666MHz.

 

Thank you.

 

[minibois]

Motherboards can overclock the memory higher than the default speed that CPU can handle.

[Syed Zaid Ahmed]

1 minute ago, minibois said:

Motherboards can overclock the memory higher than the default speed that CPU can handle.

If you have time can you explain it in little detail, I didn't quite catch up.

Thank you

[kilrath81]

7 minutes ago, Syed Zaid Ahmed said:

If you have time can you explain it in little detail, I didn't quite catch up.

Thank you

The ram is rated for higher than the default speed listed for the CPU. They usually come with a XMP profile that you enable in the bios that runs the ram at its rated spec. Its technically an overclock on the ram just like you can overclock a CPU or GPU, the difference is they are tested by the manufacturer to be stable at that specific overclock.

[Syed Zaid Ahmed]

5 minutes ago, kilrath81 said:

The ram is rated for higher than the default speed listed for the CPU. They usually come with a XMP profile that you enable in the bios that runs the ram at its rated spec. Its technically an overclock on the ram just like you can overclock a CPU or GPU, the difference is they are tested by the manufacturer to be stable at that specific overclock.

So, 2666MHz is stable MHz for Core i9 9900K and even if I put 3200MHz I'll have to set it on 2666MHz?

[minibois]

13 minutes ago, Syed Zaid Ahmed said:

If you have time can you explain it in little detail, I didn't quite catch up.

Thank you

The CPU has a memory controller that can run up to 2666Mhz, but the motherboard can tell it to run at a higher speed.

It's similar as to how a CPU runs at a certain frequency, but you can overclock it.

 

This is why - if you visit - the motherboard manufacturers website you will see it mention RAM speeds a little like this: "3200Mhz (O.C), 2933Mhz (O.C), 2666Mhz, 2400Mhz" etc.

 

So the motherboard tells the CPU to run the memory at a higher speed; which is memory overclocking.

[Syed Zaid Ahmed]

1 minute ago, minibois said:

The CPU has a memory controller that can run up to 2666Mhz, but the motherboard can tell it to run at a higher speed.

It's similar as to how a CPU runs at a certain frequency, but you can overclock it.

 

This is why - if you visit - the motherboard manufacturers website you will see it mention RAM speeds a little like this: "3200Mhz (O.C), 2933Mhz (O.C), 2666Mhz, 2400Mhz" etc.

 

So the motherboard tells the CPU to run the memory at a higher speed; which is memory overclocking.

So, if CPU for instance has 2666MHz and mobo supports 4133MHz, does it means I can put 4133MHz of RAM

[minibois]

1 minute ago, Syed Zaid Ahmed said:

So, if CPU for instance has 2666MHz and mobo supports 4133MHz, does it means I can put 4133MHz of RAM

Yes.

Whether the board will properly support is another thing..

All RAM is the same, some is just rated to work at a certain speed. The motherboard is still responsible for telling the RAM what to actually run at.

 

If the motherboard or RAM is not working properly together, it might not reach those speeds.

It's always best to check the QVL of the motherboard you have/want to get to see if it supports many kits at a high speed or not.

[Syed Zaid Ahmed]

3 minutes ago, minibois said:

Yes.

Whether the board will properly support is another thing..

All RAM is the same, some is just rated to work at a certain speed. The motherboard is still responsible for telling the RAM what to actually run at.

 

If the motherboard or RAM is not working properly together, it might not reach those speeds.

It's always best to check the QVL of the motherboard you have/want to get to see if it supports many kits at a high speed or not.

Thanks bro. I make the right decision joining LTT Forum, really appreciated.

[kilrath81]

32 minutes ago, Syed Zaid Ahmed said:

So, if CPU for instance has 2666MHz and mobo supports 4133MHz, does it means I can put 4133MHz of RAM

I dont know, depending on board whether it "Will just work" You may still have to go into the bios and enable it to run at the rams higher rated speed.

[WoodenMarker]

Intel's specs are very conservative. Going above 2666mhz is an oc and isn't officially supported but generally works. The advertised higher clocks on ram kits are oc's guaranteed to work in their configured kits by the manufacturer.