3 ms·
It's very strange that DDR5 mandates internal ECC within each physical package, but not on the longer and possibly more EMI sensitive connections between the me
by zdw 4y ago
It's very strange that DDR5 mandates internal ECC within each physical package, but not on the longer and possibly more EMI sensitive connections between the memory chips and controller.
I would have thought that the additional cost would be minimal (additional wiring on the logic board in some cases), but maybe this is just more artificial market segmentation?
- ilyt 4y agoThey have internal ECC coz that allows them to have higher yields, what could be considered faulty chip in DDR4 can be now sold in DDR5. So it is effectively cost-reducing measure for them. Exposing that to the user not only would cost extra pennies, but potentially have uses go "hey, this stick is shit, look at how many correctable errors it is producing, please replace it"
- Dylan16807 4y agoAnd LPDDR5 gets to have link-level ECC. Thinking about it, when a DIMM doesn't have extra RAM chips for ECC, you could reuse the ECC pins to run a parity bit to each chip. It would cost nothing. And with DDR5 having 2x8 ECC pins, it would work with any chip layout: x16, x8, or x4.