AMD EXPO 1.2 could supercharge Ryzen CPUs with CUDIMM support amid global DRAM crunch — full AMD CUDIMM support is on the horizon

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CUDIMM is on the way to AM5.

Trident Z5 CK
(Image credit: G.Skill)

HWiNFO, a popular system monitoring and diagnostics utility, just added support for AMD EXPO 1.2 overclocking profiles, kicking off a wave of speculation about improved support for the best RAM on the market today.. According to renowned AMD utility developer 1usmus, EXPO 1.2 is set to finally unlock CUDIMM support for AMD Ryzen processors — some of the best CPUs.

DDR5 blazes past speed limits by tapping into client clock driver (CKD) chips—paving the way for cutting-edge CUDIMMs. Without getting too deep into the technical details, the CKD acts as a signal booster. It helps keep the signals strong and clear, allowing CUDIMMs to run faster and more reliably than standard DIMMs. It allows memory manufacturers to push DDR5 speeds even higher.

Although AMD's AM5 platform is physically compatible with CUDIMMs, full support likely won't arrive until the next-generation 900-series chipsets launch alongside Zen 6 processors. According to expert 1usmus, AMD needs to optimize the CA bus—the control artery responsible for carrying commands and status signals between the processor and other components. Upgrading this internal “expressway” is key to unlocking the blistering speeds of CUDIMMs, which are already racing toward the DDR5-10000 milestone.

Intel’s Arrow Lake processors paved the way for CUDIMMs with native support for DDR5-6400 CUDIMMs, with the Arrow Lake Refresh lineup expected to boost that standard to DDR5-7200. Nova Lake will likely raise the bar even higher, perhaps explaining why AMD is strategically preparing EXPO 1.2 for its upcoming Zen 6 chips. While not all high-speed memory kits require a CKD to reach impressive speeds, the presence of a CKD is a game-changer for achieving rock-solid stability and performance at the highest data rates.

Amid today’s turbulent memory market, AMD is wisely biding its time on CUDIMM support. Ongoing shortages, fueled by unrelenting demand from AI and hyperscale data centers, have pushed memory kit prices even higher—and there’s no relief in sight. Industry experts predict these sky-high prices may not ease until 2027 or even 2028. With Zen 6 expected to debut in late 2026 or early 2027, AMD has a window to see DDR5 prices stabilize before its next major launch.

Zhiye Liu
Zhiye Liu
News Editor, RAM Reviewer & SSD Technician

Zhiye Liu is a news editor, memory reviewer, and SSD tester at Tom’s Hardware. Although he loves everything that’s hardware, he has a soft spot for CPUs, GPUs, and RAM.

8 Comments Comment from the forums
  • Gururu
    I am so confused. Is it out now or not? Does it or will it impact current AM5 processors? Who had it first Intel or AMD? Does Intel Core 200 actually use it? What sort of impact did it provide? Why does AMD biding their time help anybody?
    I know I saw a statement or two addressing these matters, but I am still confused.
    Reply
  • palladin9479
    Gururu said:
    I am so confused. Is it out now or not? Does it or will it impact current AM5 processors? Who had it first Intel or AMD? Does Intel Core 200 actually use it? What sort of impact did it provide? Why does AMD biding their time help anybody?
    I know I saw a statement or two addressing these matters, but I am still confused.
    Intel uses it but no current AMD cpu actively supports CUDIMM. Instead you need to run them in bypass mode, which treats them as regular DIMMs.

    The big benefit is that your IMC isn't required to drive the clock signal for the entire memory bus, instead only driving to the front of the DIMMs. The DIMMs have their own clock chip that will take over and drive the signal for that DIMM. In a practical sense it means much less voltage required on the CPU side.
    Reply
  • ezst036
    Admin said:
    Although AMD's AM5 platform is physically compatible with CUDIMMs, full support likely won't arrive until the next-generation 900-series chipsets launch alongside Zen 6 processors.
    So,

    Probably not a BIOS/UEFI update then on existing platforms.

    Buy the new chipset?
    Reply
  • WINTERLORD
    I'm wondering would you need new ram future ram that supports the 1.2 expo or is all ram that has expo benefit from the 1.2 amd has come up with for regular ram not cudimm
    Reply
  • thestryker
    Gururu said:
    Is it out now or not?
    The new version of EXPO is not supported by any CPU yet.
    Gururu said:
    Does it or will it impact current AM5 processors?
    No, because it requires the CPU IMC to support CUDIMMs. It should work on existing AM5 motherboards with Zen 6 CPUs however.
    Gururu said:
    Who had it first Intel or AMD?
    Intel.
    Gururu said:
    Does Intel Core 200 actually use it?
    The 200 series supports using CUDIMMs.
    Gururu said:
    What sort of impact did it provide?
    The effective impact is a more stable experience with higher bandwidth memory. JEDEC has mandated it for everything using their specifications starting at DDR5-6400 and above. Intel's ARL can run high speeds with or without using CUDIMMs, but once you get into the mid-8000s CUDIMMs are the best bet for out of the box stability.
    Gururu said:
    AMD biding their time help anybody?
    It doesn't since CUDIMMs aren't mandatory and is completely compatible with UDIMMs.
    Reply
  • WINTERLORD
    I have 7200mhz ram with expo but sense this was prior to the expo update even with a future cpu i wont be able to use the new expo unless it be a bios update or somthing?
    Reply
  • thestryker
    WINTERLORD said:
    I have 7200mhz ram with expo but sense this was prior to the expo update even with a future cpu i wont be able to use the new expo unless it be a bios update or somthing?
    For your existing modules absolutely nothing will change in any way no matter what revision of EXPO or CPU is being used. When they update/add features that only applies to things that are actually programmed with it.

    I believe EXPO is implemented at a BIOS level, but that does not mean that it adds features to hardware that doesn't support it. EXPO DRAM modules will have a profile coded to them at the factory and that's it (unless the profiles aren't locked and a user does something they probably shouldn't be). CUDIMMs require support at the memory controller level so only future CPUs will be able to utilize the CKD on them though others may work in bypass mode.
    Reply
  • palladin9479
    ezst036 said:
    So,

    Probably not a BIOS/UEFI update then on existing platforms.

    Buy the new chipset?

    This is likely new motherboard territory as CUDIMM's have additional control signals and voltage regulators. They are pin for pin compatible with DIMM slots so they will fit, but unless the motherboard, BIOS and CPU have support you can't run them in active mode.

    Like you know how if you enable EXPO in your BIOS you can see it bump up the voltage on the memory channel and SOC (memory controller is there)? With CUDIMM you don't really do that and instead the DIMM use's a clock chip to drive it's own signal and pull it's own power. And since that power for the clock signal is coming from the board and not the IMC, you can reliably run more then two DIMMs at high speeds.

    This is what servers do with FB-DIMM's and RDIMM's, only those technologies include ECC and data buffers to allow for insane amounts of memory chips per channel compared to consumer CPUs. CUDIMM took the important big, clock regeneration chips and applied it to the UDIMM standard without making it electronically incompatible so to be drop-in replaceable. Very good way to guarantee adoption.
    Reply