Intel Xeon 6556P-B socket: BGA 4368

What the Xeon 6556P-B is

The Intel Xeon 6556P-B is the 36-core efficiency-tuned member of the Xeon 6 Granite Rapids-D soldered edge stack on BGA 4368. It runs 36 Performance-cores with Hyper-Threading for 72 threads at 2.3 GHz base with boost to 3.5 GHz, backed by 144 MB of cache and a 215 W TDP. Intel launched the P-B range in the first quarter of 2025 at a 2943 USD recommended price, built on Intel 3 for single-socket edge servers.

Thirty-six cores at 215 W suit consolidation hosts, storage heads, video pipelines and inference nodes where density per watt matters more than peak frequency. The 2.3 GHz base keeps the 215 W envelope in reach for standard edge chassis, while bursts to 3.5 GHz clear control spikes. The 144 MB cache pool keeps working sets near the cores.

Against the 32-core Intel Xeon 6546P-B below it, the 6556P-B adds 4 cores for denser virtual machines at a higher power class. Against the 36-core Intel Xeon 6553P-B above it, the 6556P-B trades base frequency for a 20 W lower envelope. Zero UPI links confirm single-socket-only topologies. See Socket vs chipset: what decides whether a CPU works for how socket, platform and firmware fit together on server boards.

Socket and motherboard compatibility

The 6556P-B fits BGA 4368, a 4,368-ball soldered package measuring 77.5 × 50 mm. The chip is soldered once at the factory and stays with the board for life, so there is no retention mechanism and no aftermarket mounting choice. Cooling is part of the board design for the 215 W class with an 85 degree case limit.

Board choice follows the server vendor list for Granite Rapids-D edge systems. Memory is 4-channel DDR5 ECC fixed per board, and expansion rides on 32 Gen 5 plus 16 Gen 4 PCIe lanes. A board revision needs firmware that knows the Granite Rapids-D stepping. Moving from any other socket is a full platform change with board, memory and heatsinks replaced together.

Memory, PCIe and cooling

Memory on BGA 4368 is DDR5 ECC in 4 channels, up to 6400 MT/s on qualified boards. Four channels keep 72 threads supplied in consolidation, storage and inference mixes. Some boards qualify at 5600 MT/s instead, so the vendor memory list governs exact speeds and population rules.

PCI Express connectivity is Gen 5 with x32 lanes plus Gen 4 with x16 lanes from the CPU. That lane budget feeds NVMe storage, 25 and 100-gigabit networking and accelerators on a single-socket edge node. AVX-512 with two FMA ports and DL Boost accelerate inference where the workload uses them.

Cooling follows the board vendor list for the 215 W class with vendor-qualified heatsinks. No cooler ships with the tray server part. Firmware power limits can cap draw below the default where a cabinet demands it, at some cost in sustained clocks.

Upgrade paths

On the same package, the path up from the 6556P-B is the 36-core Intel Xeon 6553P-B for higher clocks on BGA 4368 boards where power and cooling allow. The 40-core Intel Xeon 6716P-B follows for more cores. Each move needs a board and BIOS that already support Granite Rapids-D.

The step down to the 32-core Intel Xeon 6546P-B trims cores for a lower price. A move to BGA 5026 is a different soldered platform with 64 cores and 8 memory channels for denser nodes. That change replaces board, memory and cooling from scratch.