SODIMMs meet advertised speeds out of the box.

[OFaceSIG]

So here's question I searched for and I couldn't find it.

Why does laptop memory work out of the box at it's rated speeds and not desktop memory?

My 11th Gen Intel Framework's Samsung memory runs at 3200MHz out of the box. My AMD Framework's SK Hynix memory runs at 5600MHz out of the box.

Yet desktops don't do this. Is this just to simplify deployments of laptops so they certify the memory at faster JEDEC speeds?

 

[dasa]

You can get desktop RAM with higher JEDEC speeds but usually with really loose timings as they are limited by the vdimm.
Most XMP kits start at a low speed for stability and allow you to increase V and performance with XMP.
A lot of laptops don't support XMP so I guess you just see more of one type of kit for laptops and more of the other for desktops.