1usmus reveals AMD EXPO 1.2 details
AMD EXPO 1.2 reportedly adds MRDIMM support, full CUDIMM support expected with Zen 6
AMD EXPO 1.2 is now said to bring a wider memory profile update than previously expected. According to 1usmus, the new revision adds support for module geometry and MRDIMM memory. CUDIMM and CSODIMM are also part of the EXPO 1.2 path, although CUDIMM support is still limited on current firmware.
Only partial support, full support with Zen6
The developer claims AGESA 1.3.0.1 does not yet include full CUDIMM support. AMD is reportedly preparing that part for Zen 6, which suggests current AM5 platforms may expose EXPO 1.2 metadata before full clocked module support is available. This follows earlier coverage when HWiNFO added AMD EXPO 1.20 support and 1usmus linked the update to CUDIMM memory support.
Due to the DRAM shortage, support has also been added for three Chinese module manufacturers: RAMXEED Limited Conexant, Rui Xuan (formerly Rei Zuan) and Fujitsu Synaptics.
That's all the surprises there are.
— 1usmus 🇺🇦 (@1usmus) April 24, 2026
CUDIMM and CSODIMM modules include a Client Clock Driver , which is used to improve signal integrity at higher DDR5 speeds. Existing AMD platforms do not support the clock drivers on these modules, or may run them at reduced capability. MRDIMM is a different DDR5 module type aimed at data center and enterprise systems, with multiplexing used to increase bandwidth and capacity.
EXPO 1.2 also reportedly adds new fields for tREFI, tRRDS, tWR, ULL Enable and VDDP voltage. ULL stands for Unified Latency Lock, according to 1usmus.
Support for 3 new Chinese brands
1usmus also claims AMD added support for three additional module vendors due to the DRAM shortage. The names posted are RAMXEED Limited Conexant, Rui Xuan, formerly Rei Zuan, and Fujitsu Synaptics. AMD has not published a public EXPO 1.2 specification or vendor list.
Now rolling out with ASUS boards
ASUS has already started rolling out beta BIOS support for EXPO 1.2 on X870 boards. ASUS listed EXPO 1.2 support in new beta BIOS builds for its AM5 motherboards. If you are not afraid of using beta BIOSes, and you happen to own CUDIMM memory, well, now you can technically use such modules, if they work for you, let us know!
Source: 1usmus
