Intel patent shares details L4 cache potentially used in Meteor Lake
An Intel patent shares details about the operation of Intel’s L4 cache, Adamantine. Recently, a Linux patch suggested that Intel will use such cache in its upcoming consumer Meteor Lake CPUs.
The patent states that Intel’s ‘next generation SoC architecture’ may have ‘large on-package caches’, tech website VideoCardz was the first to notice. These should serve as an L4 cache. The cache is called ‘Adamantine’ or ‘ADM’ and, according to Intel, should ‘enable new applications’.
For example, the access time to this L4 cache should be much shorter than the access time for dram. According to the patent, Adamantine can therefore be used, among other things, to improve communication between the CPU and the security controller. Boot times should also be reduced by using L4 cache. The L4 cache would save data when resetting the PC.
There have been reports for some time that Intel will introduce L4 cache, specifically in its upcoming Meteor Lake processors. Earlier this month, mentions of this appeared in a Linux patch, Phoronix noted. The patch in question referenced ‘ADM/L4’ in Meteor Lake, but shared no further details. ADM now appears to stand for Adamantine.
The newly noticed patent does not specifically mention the term Meteor Lake, but does contain references to this CPU generation. Images from the patent show a CPU with two Redwood Cove cores and eight more efficient Crestmont cores on one ’tile’, the term Intel uses for chiplets. Specifically those cores are used in Meteor Lake. The diagram also shows a separate GPU tile with 64 execution units and a social tile. It has been known for some time that Meteor Lake will have a design with such tiles.
It is not yet known how much L4 cache Intel’s upcoming processors will have. This may differ per model. Leaker Moore’s Law is Dead stated in a recent video that the company is currently doing internal testing with caches from 128 to 512MB. In the long term this could amount to more than a gigabyte. Moore’s Law is Dead often shares information about unreleased products, although the accuracy is variable.
Intel’s L4 cache patent (left) and the previously confirmed Meteor Lake build, with a CPU chiplet, GPU chiplet and SoC chiplet