26 Nov
2024
26 Nov
'24
2:16 p.m.
From: David Collier-Brown via talk <talk@gtalug.org>
Apparently at the moment, most RDIMM DDR5 is EC8 ECC which is 80bit. And most UDIMM is EC4 ECC which is 72 bit. I don't believe there is any requirement for it to be that way.
Oh my goodness sake (;-))
That /really/ takes me back: I learned B on a DPS-8, which used 72-bit double-words.
The DPS-8 surely had parity or ECC on top of the 72 data bits. The DPS-8 was a 36-bit word system. A logical descendant of the IBM 701 (which had 72 Williams Tubes for RAM). Honeywell and UNIVAX hung on to 36-bits much longer than IBM. (The first 36-bit word machine I used was an IBM 7040/44 but I only used FORTRAN on it.)