Intel Xeon w9-3495X socket: LGA 4677

What the Xeon w9-3495X is

Intel positions the Xeon w9-3495X as the 56-core member of the Sapphire Rapids Xeon W family for LGA 4677 boards from February 2023. 56 cores with hyperthreading give 56 cores and 112 threads, with base at 1.9 GHz and up to 4.8 GHz turbo. The package carries 105 MB of Smart Cache. The 350 W envelope needs a high capacity heatsink with front to back airflow and a chassis rated for continuous full load. Workstation cooling follows the board vendor list with vendor qualified air or liquid for this 350 W class.

DDR5-4800, 8 channels, up to 4 TB with ECC feed the cores for workstation duty, and matched kits hold the rated speed. One hundred twelve Gen5 lanes per CPU wire multiple GPUs and NVMe on W-3400 boards, with the lane count fixed per board for slot splits. Single socket operation keeps workstation design simple with one CPU per board and no multi socket fabric.

Flagship workstations for rendering and simulation take this high core part with the full 8-channel layout, where thread density carries the largest jobs on one socket. Boards need a W790 chipset with the Xeon w9-3495X on the CPU support list, and memory choice stays with DDR5 RDIMMs. The Socket vs chipset: what decides whether a CPU works guide covers board choice, and Intel Xeon w7-3445 shows a nearby option on the same socket.

Socket and motherboard compatibility

The w9-3495X fits LGA 4677 on single socket workstation boards with LGA 4677 retention and workstation power delivery. Board lists must name the Xeon w9-3495X part for qualification.

W790 chipset choice decides IO breadth and overclocking headroom on X SKUs rather than CPU fit. A BIOS that lists Sapphire Rapids W from February 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.

Memory, PCIe and cooling

DDR5-4800, 8 channels, up to 4 TB with ECC feed the cores for workstation duty, and matched kits hold the rated speed. 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.

One hundred twelve Gen5 lanes per CPU wire multiple GPUs and NVMe on W-3400 boards, with the lane count fixed per board for slot splits. Lane bifurcation follows board firmware, so slot population rules come from the board manual.

The 350 W envelope needs a high capacity heatsink with front to back airflow and a chassis rated for continuous full load. Workstation cooling follows the board vendor list with vendor qualified air or liquid for this 350 W class. The FCLGA4677 package uses a carrier with even mounting pressure. Paste and torque sequence follow the heatsink maker specification for 350 W parts.

Upgrade paths

On LGA 4677 the upward moves are higher core Xeon W parts on the same W790 board where render threads grow, with X SKUs adding tuning headroom. For this 56-core SKU, memory growth to full channel population and GPU additions often help more than clocks.

Outside this SKU, Intel Xeon w7-3445 (Xeon w7-3445) on LGA 4677 trims or adds cores for lighter or denser loads. A move to W-3400 adds channels and lanes, while a move to server Platinum needs a new board and memory plan.