SDR in a DDR slot ?

I know DDR can not work in an SDR slot - but how about the other way round ?

For use with AOPEN AX4B PRO-533

simple answer: NO Go get the right ram for the right slot.

      • I think they’re physically different: the last PC I put together had slots for both, and had two sets of slots, if you get my drift…

Nope, completely incompatible. SDR SDRAM is 168pin, 3.3V. DDR SDRAM is 184pin, 2.5V.