kingcake wrote on 2026-11-12, 23:54:

So there is some performance benefit to 168-pin EDO? I had (wrongly) assumed it was a simple reorg for the newer bus.

I don't expect standard PC chipsets to implement /OE control for EDO, so likely you won't see any performance benefit. Any design that has both PS/2 and DIMM slots has to cope with /OE-less SIMMs in the PS/2 slots. The /OE pin on EDO DIMMs is probably only used in special-purpose designs that are not meant to be compatible with PS/2 SIMMs.

In PC mainboards, I expect /OE on the EDO DIMM socket to be permanently grounded (at least in EDO mode, didn't check SDRAM mode), effectively operating EDO RAMs the same way as they work on PS/2 SIMMs.

OK, I though that OE# is needed to Hi-Z inactive bank during interleaving but as output can be controlled via RAS#/CAS# then seems not needed...