Sanity Check - CPU / Memory Combo

[Derek W]

Morning All,

Following on from a thread i started and the end of last year in General Hardware where I was looking at a new build for Sketchup / D5 Render productivity PC I'm now in a position where i can push the button for the build with a few tweaks.

I'm currently looking at this CPU https://www.overclockers.co.uk/inte...ocket-lga1700-processor-retail-cp-6az-in.html and 64GB ram https://www.overclockers.co.uk/king...800c40-5600mhz-dual-channel-ki-my-29w-ks.html with the intention of upgrading to 128GB with this board https://www.overclockers.co.uk/asus...-lga-1700-ddr5-atx-motherboard-mb-6kq-as.html.

Now reading through the CPU info I was slightly confused by this statement

- Up to 32GB DDR5-5600 memory, up to 64GB DDR5-5200 memory and up to 128GB DDR5-3600 memory

Does this mean that the memory I'm looking at isn't compatible with the CPU or will the clock speed be reduced to 3600hz if i use the full 128GB?

Thanks for any knowledge on this subject.

 

[heatonpkmassive]

Clockspeed will be reduced to 3600Mhz if you use the 128Gb you're planning to use.

 

[Derek W]

Thanks

 

[Tetras]

Does this mean that the memory I'm looking at isn't compatible with the CPU or will the clock speed be reduced to 3600hz if i use the full 128GB?

Intel 13th gen CPUs support a maximum of 5600 in DDR5 (this is @ JEDEC timings, not with XMP enabled), but Intel derates the CPU's memory controller to only 3600 for 4 dual rank sticks (128GB).

There have been tests with 192Gb and 256GB that show they're capable of significantly higher than 3600, but officially that's all that Intel supports.

But, let's be honest, literally nobody (except the likes of Dell, Lenovo) pays any attention to the official specs. You might be better off just going straight for 96GB, but a scoot around on reddit and other forums should tell you what 13900K users are achieving with 128GB+ on the current BIOS.