Beyond the memory specifications?

[Haswellx86]

Intel's specs sheet of 12900KS show that it only supports DDR5 up to 4800MHz, yet we can still put 6400MHz memory in our systems, how?

[Levent]

That only means they are officially rated to run up to 4800mhz. Anything above that is not guaranteed from the manufacturer, that doesnt mean they cant run it. IIRC DDR5-4800 is also the lowest frequency JEDEC standard.

[RONOTHAN##]

Overclocking. The memory controller can be set to run at any speed you want it to, it's just that Intel and all the board vendors only guarantee 4800MT/s to work. Given the right amounts of voltage and a good memory topology, it'll do 6400MT/s

[Somerandomtechyboi]

Spec is only the guaranteed speed itll run, usually you can run much higher but that depends on your ram ics, cpu imc, and mobo

 

I suggest not bothering with ddr5 atm as its overpriced asf and has very little performance benifit over ddr4 for now, although you can get futureproof ddr5 in the form of hynix bare pcbs off ebay (~100$ for 16gb stick) which may be capable of >7000 if you get the same ic as those high bin kits (you can request specific ic but i havent found any thaiphoon burners of highend ddr5 kits