It seems motherboard manufacturers will ourt both DDR4 and DDR5 based motherboards. The upcoming ASUS Z690 motherboards featuring LGA1700 socket for Intel Alder Lake CPUs have been listed by the Eura... ASUS Z690 motherboards listed give you a choice - there are DDR5 and DDR4 variants
Hmm wouldn't the CPU need a memory controller for both then? EDIT: Ah Z is Intel and they were going to go for that. X is AMD. Never got the 590 this gen (570 and 550 a bit later instead of 590 and 570 I think is how that went.) but a 690 could happen thus this momentary confusion.
In previous years there have been a few boards with DDR3 and DDR4 slots on the same board (although you couldn't use both at the same time).
that is exactly what it means it has long been known that alder lakes integrated memory controller supports DDR4 and DDR5, just like skylake did with DDR3 and DDR4. -andy-
The intel alder lake CPU (all versions) are compatible with DDR4, DDR5, LPDDR4X, and LPDDR5. It's up to motherboard manufacturers which DDR PHY to install.