Ampere Altra Max M128-28 socket: LGA 4926

What the Altra Max M128-28 is

The Ampere Altra Max M128-28 is a 128-core server processor with a 2.8 GHz sustained frequency. It runs 128 single-thread Arm v8.2+ cores with no turbo, so 128 cores give 128 threads. Cache is 1 MB of L2 per core plus a 16 MB shared system cache on a 7 nm process. Power is rated at 230 W max with about 150 W usage power in a 4926-pin FCLGA package with order part number AC-212823002.

Full 128-core density below the 3.0 GHz flagship trims power while keeping core count, which is why the M128-28 at 2.8 GHz suits dense racks with power caps. Ampere sold the M128-28 in the Max lineup. The chip supports enterprise RAS with coherent two-socket links.

Full density with a 230 W envelope suits dense cloud servers with DDR4 memory. That is why the M128-28 shipped in scale-out racks.

Socket and motherboard compatibility

The M128-28 fits LGA 4926 dense servers with Altra Max support. It needs a 4926-land board with Ampere firmware and a BIOS that lists the M128-28. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Dense scale-out servers are the natural match. Boards listing the M128-28 accept the chip with a 230 W heatsink.

Memory, PCIe and cooling

Memory is eight channels of DDR4-3200 ECC through the on-chip controllers, up to 4 TB per socket. PCIe Gen4 with 128 lanes per socket feeds storage and networking, 192 lanes in two-socket systems. Cooling uses server heatsinks rated for 230 W.

Upgrade paths

On the same socket, a move to an Altra Max M128-30 such as Ampere Altra Max M128-30 adds 200 MHz at 250 W when frequency matters. An Altra Max M128-26 such as Ampere Altra Max M128-26 drops to 2.6 GHz at 190 W.

Newer AmpereOne needs a new platform. The LGA 4926 page lists the range. Note: usage power 150 W per datasheet (Newegg lists 154 W); TDP 230 W agreed.