A patent shared by Underfox on Twitter shows that AMD is also considering dipping its toes into the hybrid CPU game, featuring a mixture of high-performance and low-power cores. This is similar to Intel’s Lakefield and upcoming Alder Lake parts which follow ARM’s Big.Little philosophy, although with certain modifications.
As you can see above, there are two different processor clusters, one featuring two “Big” or high-performance cores and the other consisting of two “little” or low power cores. Interestingly, while the first two levels of cache (L1 and L2) are exclusive to each cluster, the L3 cache is shared across the two. Usually, this would impose a significant latency penalty, but since this is just a PoC that’s not quite important just yet.
In case you didn’t know, unlike Intel, AMD doesn’t have its own low-power core architecture based on Zen 2. There’s the 6W Dali design, but it’s basically Zen scaled down to low-power|low-frequency config. The last small core from AMD was the Jaguar core which powers the present-gen consoles. Considering how efficient Zen 2 really is though, it shouldn’t be hard to cook up a replacement. We might just get two clusters of same cores running at different clocks (different bins).
Lastly, please don’t forget that this is just a patent, so if AMD does plan to invest in an hybrid CPU which I don’t think they should, it’s several years away.