Intel Xeon Phi 7250F socket: LGA 3647

What the Xeon Phi 7250F is

The Xeon Phi 7250F brings Knights Landing to LGA 3647 for fabric dense nodes with stacked memory. It launched in October 2016 with 68 cores at 1.4 GHz base and up to 1.6 GHz boost at 230 W. Intel targets clusters that need dense cores with high power budgets.

Thirty four megabytes of L2 with 512 KB per core carry tiles without L3. Four threads per core give 272 threads. The mesh joins tiles, memory and I/O on die.

Sixteen gigabytes of on package MCDRAM deliver over 400 GB/s beside DDR4 pools up to 384 GB. The process is 14 nm. The multiplier is locked. AVX-512 units speed vector loops.

Buyers choose the board at order time with memory and cooling tier. The 230 W rating needs 2U airflow. MCDRAM runs as cache, flat NUMA or hybrid per job.

Socket and motherboard compatibility

The Xeon Phi 7250F fits LGA 3647 on KNL server boards with DDR4 slots. Makers list Knights Landing with late 2016 BIOS builds. Early stock may need an update.

Bootable host builds run Linux directly on the chip. The F suffix marks the 230 W variant of the 7250. The Socket vs chipset: what decides whether a CPU works guide covers matching.

Single socket HPC nodes are the deployment. Growth means more LGA 3647 nodes. Power needs metered racks for 230 W per socket.

Memory, PCIe and cooling

DDR4 in six channels up to 384 GB suits dense jobs with ECC. Sixteen gigabytes of MCDRAM lift bandwidth bound loops. Test cache and flat modes per code.

PCIe 3.0 with up to 36 lanes from the CPU serves HBAs and NICs. Boards split lanes between risers and NVMe. Fabric options cut add in cards.

Cooling follows server practice with vendor heatsinks for 230 W classes. No cooler ships in the box. ECC guards DDR4 memory.

Upgrade paths

On the same socket, the Intel Xeon Phi 7250 shares 68 cores at the same clocks at 215 W for standard racks. The Intel Xeon Phi 7230F gives 64 cores at 230 W for fabric aisles. Both share LGA 3647 boards.

The Intel Xeon Phi 7290 moves to 72 cores for top nodes. It needs the same boards.

Past HPC nodes move to Xeon Scalable. The Phi 7250F covers late 2016 clusters where dense fabric cores must deploy.