Intel's Clearwater Forest E-Core Server Chip at Hot Chips 2025
16 days ago
- #Intel
- #Skymont
- #Server-Chips
- Intel's Clearwater Forest uses Skymont E-Cores, offering significant performance improvements over previous Crestmont E-Cores.
- Skymont cores are packed into quad-core clusters with a 4 MB L2 cache, enhancing performance density.
- The compute dies are fabricated on Intel’s 18A node, benefiting from improved density and power delivery.
- Clearwater Forest features 3D stacking with compute dies on Intel 3 base dies, hosting mesh interconnect and L3 slices.
- The chip has three base dies, totaling 288 cores, doubling the core count of Sierra Forest.
- IO dies use the Intel 7 process and are reused from Sierra Forest, streamlining logistics and reducing costs.
- Skymont clusters sustain 128 L2 misses, crucial for hiding memory latency and achieving high bandwidth.
- Clearwater Forest boasts a 576 MB L3 cache, providing a potential hitrate advantage over competitors.
- The chip supports DDR5-8000, offering ~1.3 TB/s of DRAM read bandwidth and 96 PCIe Gen 5 lanes per chip.
- Intel claims 20 Clearwater Forest racks can match the performance of 70 racks using older P-Core servers.
- Skymont cores now compete closely with P-Cores, marking a significant evolution in Intel’s E-Core strategy.