ASUS has showcased an interesting DDR5 to DDR4 prototype board that would let you use DDR4 DIMMs on any Z690 DDR5 motherboard.
ASUS's DDR5 To DDR4 Adapter Board Shown Off, Demoed With Z690 APEX Motherboard
DDR5 memory is really expensive to get hands-on and that's even if you can find it since it has an impending shortage which won't get better till late next year. As such, ASUS has come up with an interesting prototype board that lets you use DDR4 memory sticks on any DDR5 motherboard. In a video by Lin Dabing Bing, you can not only see the test board but also it running a DDR4 module on a DDR5 motherboard.
The adapter board which is branded under the ASUS ROG brand is a very tall unit so it might have some issues with certain air coolers. The adapter board is said to feature all the necessary power circuitry on itself considering that motherboard makers removed most of the power management from Intel's 600-series boards that feature DDR5 support. This is done because the power/voltage chips (PMIC) were moved to the DDR5 modules whereas, in DDR4, the power managing was done on the motherboards.
The top of the adapter board features the standard DDR4 DIMM slot while the bottom slots in on any DDR5 DIMM slot. The YouTuber showed a demonstration of the Z690 motherboard running a DDR4 memory module and it was also detected within the BIOS even though the motherboard is officially DDR5 compliant. It is also explained that this is an early prototype so that's why the PCB height is too much but that's something that ASUS is focusing on to improve in future iterations. The test board also features a reserve spot for a 4-pin connector in case the power delivery is not enough for the boot sequence.
It is not stated if the adapter board will be headed to the retail segment since it is still a prototype and even the ROG Maximus Z690 APEX used in the demo was a test board specifically designed to test DDR5 to DDR4 compatibility but it will definitely make things easier for users if DDR5 availability remains an issue throughout 2022.
News Source: HXL: