The Firestorm cores are capable of issuing two 128bit stores per cycle [1], giving a bandwidth of 102.4 GBps. This matches the experiments by Andrei with mixed

The Firestorm cores are capable of issuing two 128bit stores per cycle [1], giving a bandwidth of 102.4 GBps. This matches the experiments by Andrei with mixed reads/writes [2], and I have personally verified that it is attainable for pure write workloads to L1 as well as L2. This does not mean 102.4 GBps is achievable on a single core, but if L2 bandwidth is the limiting factor it very well could be. [1] https://dougallj.github.io/applecpu/firestorm.html https://dougallj.github.io/applecpu/firestorm.html [2] https://www.anandtech.com/show/17024/apple-m1-max-performance-review/2 https://www.anandtech.com/show/17024/apple-m1-max-performanc...