One of the most significant costs associated with acquiring an Alder Lake machine today is memory, particularly when an enthusiast want to use DDR5. Due to component shortages, most notably the power management controllers required for each DDR5 module, DDR5 prices are rapidly increasing, with some scalpers demanding $1000+ for simple memory kits.
According to a preview video broadcast today on YouTube by Bing as spotted on Anandtech, who is assumed to be an ASUS ROG employee, the firm has been working on a solution that will allow users who purchase ASUS Z690 motherboards equipped with DDR5 to utilize them with DDR4. Until today, there was no way to run both DDR5 and DDR4 on the platform, as Intel confined the platform to either DDR5 or DDR4 per motherboard. Bing describes the new add-in card they've been prototyping in the video.
basically, it goes like this; start with a DDR5 board such as the ROG Apex, insert the carrier card into a memory slot, then top it off with certified DDR4.
Clearly, this is a more complicated scenario than merely using this converter card. DDR5 and DDR4 differ in more than just a notch – DDR4 uses a single 64-bit memory channel per module, whereas DDR5 uses twin 32-bit memory channels per module. The main difference is that DDR5 does power management on the module level, but DDR4 relies on motherboard-based power management, which must be considered. Additionally, adding a carrier card lengthens memory traces, which may reduce the signal's quality.
ASUS does this by enabling the ROG Apex DDR5 to function in DDR4 mode via a specific BIOS patch. This means that the memory slots' traces, while designed for DDR5 operation, are converted to DDR4 mode. Then, on the carrier card, this takes the 5V power signal and runs it through the equivalent of the motherboard's power management, as well as controlling the data lines to ensure signal, latency, and power integrity, among other things. This is still very much a prototype. It appears as though they're prioritizing getting it to run on a single motherboard with a single memory kit before optimizing it. According to Bing, the carrier card is somewhat tall, and there is potential for further optimization before ASUS offers it as a retail product. Additionally, a broader range of validation is likely required.
Additionally, the DRAM traces have been expanded, which may result in instabilities, which is why it appears to be tested with only one type of memory at the moment, which appears to be G-Tridentz Skill's Royal. The adapter requires the installation of a special UEFI version that supports DDR4 memory, but this may be the smallest obstacle in this bypass effort from ASUS' ROG team.
ASUS is Developing a DDR4 to DDR5 RAM Converter Adapter
