Intel has verified that the forthcoming Meteor Lake series of processors will incorporate an L4 cache, a feature comparable to the eDRAM seen in their Broadwell platform.
The news initially surfaced in recent Linux patch notes discovered by Phoronix, though further technical specifics regarding Meteor Lake's implementation were not divulged. A December 2020 Intel CPU patent filing was scrutinized and revealed references to "on-package caches" within the next-generation architecture. The "Adamantine" memory, in particular, will be reachable from any block within the SoC. Intel's primary objective for employing the L4 cache is to bolster optimization and security for the CPU, which will serve as the "host." Moreover, the cache will be retained during reboots, eliminating the need for time-consuming startup and reboot procedures.
The L4 cache is an extra layer of cache located outside the processor cores but inside the CPU package. It plays a crucial role in reducing latency with RAM and offering direct access to PCIe lanes. Although not as fast as L3 cache, the L4 cache surpasses RAM in speed and can accommodate more data and instructions. This enhances performance in specific applications and workloads.
According to Intel's most recent roadmaps, the Meteor Lake CPUs are projected to launch in the latter half of 2023. The company has yet to disclose which CPU from the new series will debut first.