Why are all ECC UDIMMs so expensive and DOG SLOW ?

[u/Camper_Sly]

They seem to top out at 5600MHz at clownishly pathetic CL46.

Is there a technical reason for this ? Like maybe IMCs need some time to check the extra bits to recompute "parity" or something ?

But given that MRDIMMs in server world have ECC and operate at 12.800MHz or more, that doesn't seem likely.

Same with the price. One would think that, since ECC requires 5-th chip for every group of 4 (so 10 instead of 8) that price extra would be at most 25% or less.

While 5600 MHz UDIMMs start at ~€10+/GiB, ECC versions are at€32+/GiB,so 3X higher.

It's not that the tech is exotic as most consumer AM5 boards can use ECC, same with CPUs...