Intel Xeon Gold 5423N socket: LGA 4677

What the Xeon Gold 5423N is

Buyers meet the Xeon Gold 5423N as the 20-core member of the 4th Gen Xeon Scalable family for LGA 4677 boards from January 2023. 20 cores with hyperthreading give 20 cores and 40 threads, with base at 2.1 GHz and up to 4.0 GHz turbo. The package carries 37.5 MB of Smart Cache. The 145 W envelope fits standard server heatsinks with front to back airflow.

DDR5-4000 in 8 channels with ECC feeds the cores for edge duty, and matched DIMMs hold the rated speed across the population. Forty eight Gen4 lanes per CPU wire NICs and NVMe on edge boards with the C741 class chipset, and the lower lane count matches the single socket edge design. Single socket operation keeps board design simple with one CPU per node.

Virtualized network functions and edge aggregation take this footprint with carrier features, where deterministic throughput matters more than raw core count. Server boards need a C741 class chipset with the Xeon Gold 5423N on the CPU support list, not W790 workstation boards. The Socket vs chipset: what decides whether a CPU works guide covers server board choice, and Intel Xeon Gold 6442Y shows a nearby Xeon Gold option on the same socket.

Socket and motherboard compatibility

The 5423N fits LGA 4677 on single socket server boards with LGA 4677 retention and server power delivery. Board lists must name the Xeon Gold 5423N suffix part for qualification. W790 workstation boards target W-series chips instead, so a server SKU will not post there even though the contact count matches.

Server chipset choice decides management and IO breadth rather than CPU fit. C741 class boards carry BMC management, multiple NICs and NVMe backplanes for this power class. A BIOS that lists Sapphire Rapids Gold and Platinum from January 2023 covers the part, while early firmware may need an update for specific stepping IDs. Check the board CPU list before mixing this SKU with other steppings in single socket nodes.

Memory, PCIe and cooling

DDR5-4000 in 8 channels with ECC feeds the cores for edge duty, and matched DIMMs hold the rated speed across the population. Population with matched RDIMMs holds the rated speed, and eight channel operation needs one DIMM per channel at minimum for full bandwidth. Capacity reaches 4 TB per socket with high density DIMMs, which suits in memory work on 20 cores.

Forty eight Gen4 lanes per CPU wire NICs and NVMe on edge boards with the C741 class chipset, and the lower lane count matches the single socket edge design. NICs for edge traffic and local NVMe attach directly to CPU lanes for low latency. Lane bifurcation follows board firmware, so slot population rules come from the board manual.

The 145 W envelope fits standard server heatsinks with front to back airflow. The 77.5 × 56.5 mm FCLGA4677 package uses a server carrier with even mounting pressure. Paste and torque sequence follow the heatsink maker specification for 145 W parts.

Upgrade paths

On LGA 4677 the upward moves are higher core Xeon Gold parts where VM counts grow, or adding a second Xeon Gold 5423N socket where boards allow a move to a dual socket board. For this 20-core SKU, memory growth to full eight channel population and NIC additions often help more than clocks. Moving from DDR5-4000 in 8 channels to fully populated channels lifts bandwidth without a CPU swap.

Outside this SKU, Intel Xeon Gold 6442Y (Xeon Gold 6442Y) on LGA 4677 trims or adds cores for lighter or denser loads. Platinum parts add UPI breadth for four socket and eight socket fabrics, while Silver parts cut cost for single purpose hosts. A move to another socket needs a new board and memory plan, so socket local growth comes first.