Processor manufacturer Intel revealed the first Xeon server processor with the Efficiency-core genre Clearwater Forest at Hot Chips. This processor is the first Xeon series of Intel's next-generation Intel 18A process. It is expected to be launched in 2026, with built-in 288 efficiency cores, which will bring significant efficiency and performance improvements to the data center.
Core Technology and Architectural Innovation The Clearwater Forest series is seen as a spiritual new generation of the Sierra Forest series, the Intellectual E-core Xeon processor, but brings more significant architectural upgrades. In addition to using the new Darkmont E core, these cores have a wider 3×3 decoding engine, deeper intercourse execution channels, and enhanced execution. According to Intel's data, Darkmont's E-core IPC was about 17% higher than the previous generation Crestmont's E-core.
In terms of, it exceeds 1,152MB of cache memory, and every four cores share 4MB of L2 cache. The L2 cache-frequency width is also doubled compared to the previous generation of the Sierra Forest series. With up to 288 core configurations, the Clearwater Forest series is expected to be a monster-level product that handles multi-operation network services and AI recommendation work.
Clearwater Forest is one of the first actual testing platforms for Intel 18A processes. This Intel 18A stage combines RibbonFET transistors with backside power supply technology, which is seen as the key to Intel's dominant position in density and power efficiency in recent years due to tyre-electricity and AMD. By separating power supply and signal paths, Intel said it can achieve higher single utilization and lower voltage drops, which are important for super-large scalers.
Intel emphasized that Clearwater Forest's design philosophy is not to pursue the highest efficiency of single cores, but to focus on scale applications. In the data center area, the goal is to supplement the performance gap per watt and is seen as a response to the AMD EPYC series competition. Although it may not rank at the top of basic tests such as high-performance computing or AI training, Intel predicts that it will still be ahead of the list in terms of raw execution numbers and total processing volumes.
Intel emphasizes that a dual-slot Clearwater system can theoretically support over 1,000 virtual CPUs (vCPUs) per rack, and has a 3.5-fold increase in performance per watt than the previous Xeon processors. Compared to AMD's 128-core EPYC Bergamo server processor, Clearwater adopts a completely different strategy. AMD core supports SMT, AVX-512-level vector unit and higher single execution performance, while Intel focuses on how to stuff more work into the rack without exceeding power budget. Although comments suggest that AMD will deliver more hardware execution processors a year before Clearwater Forest shipment, Clearwater Forest's single execution performance may still be advantageous in specific intensive jobs.
For decades, Xeon server processors have been synonymous with P core (Performance-core), but the emergence of Clearwater Forest predicts a change in Xeon definition. Intel expects this processor to redefine the appearance of Xeon, no longer just a new generation of updates, but will focus from a basic perspective to maximizing operating and energy efficiency within the machine. Intel emphasized that whether this efficient server processor can win customers' youth will be a key to its future development.