AMD EPYC 7Y43 socket: SP3

What the EPYC 7Y43 is

Released in March 2021, the AMD EPYC 7Y43 targets large cloud deployments with 48 cores and 96 threads. Milan cores run 2.55 GHz base with up to 3.6 GHz boost, backed by 256 MB of L3 plus 24 MB of L2. The 280 W rating sets server cooling and power delivery.

Memory support covers DDR4-3200 ECC, 8 channels, up to 4 TB per socket. Eight channels feed virtual machines and databases, and ECC corrects single-bit errors during continuous duty. Gen4 lanes serve NVMe, NICs and accelerators, 128 per socket and 160 across two.

Numbered 7-series SKUs serve large cloud and enterprise deployments with tuned clocks for dense racks. The 256 MB of L3 keeps tenants fed while base power stays inside the 300 W class. A nearby standard option is AMD EPYC 7643 on the same socket.

Socket and motherboard compatibility

The EPYC 7Y43 fits SP3 on single or dual socket server boards with LGA retention and server power delivery. Board lists must name the exact SKU for qualification.

Memory population, lane splits and cooling follow the server board design. Two-socket boards share the 160-lane budget across both processors. The CPU cooler compatibility by socket guide shows how platform choice maps to generations.

Memory, PCIe and cooling

DDR4-3200 ECC, 8 channels, up to 4 TB per socket. Matched RDIMMs hold the rated speed across all populated channels.

128 PCIe Gen4 lanes per socket, up to 160 in 2P wire NVMe, NICs and accelerators. Lane budgets decide how many devices run at full speed.

Cooling belongs to the server maker across the 280 W band with front-to-back airflow. No boxed cooler exists. Paste service follows the maker manual.

Where this Milan part fits

The Milan stack spans 8 to 64 cores, and this 48-core SKU sits where core licensing, power caps or per-core fees shape the order. Fewer, faster cores beat more, slower cores for licensed databases, while dense virtualisation takes higher counts. The 256 MB L3 keeps working sets close on both shapes.

Single-socket boards cut idle draw for edge racks while dual-socket boards serve dense virtualisation. Populate all eight memory channels for full bandwidth on either shape, since empty channels cost throughput on memory-bound work. The EPYC 7Y43 needs a board that lists it by name with the right firmware.

Boards need firmware with Milan support before the chip posts, so buyers confirm the BIOS revision with the vendor. Memory population order follows the board manual with primary slots first, and all eight channels should fill for full bandwidth on memory-bound work.

Inside the Milan stack this SKU pairs 48 cores with 256 MB L3 of L3, about 5.3 MB per core, set against 48 cores against 48 cores with a higher 280 W envelope in [[cpu:EPYC 7643]]. Base power of 280 W puts it in the family band that spans 95 W to 280 W, which decides heatsink size and rack power budgets.

Upgrade paths

On SP3 the moves run along core count within the same board class, up to flagships such as AMD EPYC 7643 where validated. Core growth needs no board change when the maker lists the part.

Beyond the series the replacement is a whole server on newer platforms. The How to find your CPU socket type guide explains when a platform change pays off.