Apple M series is also aarch64 architecture, isn't it? Could you explain more why you expect Ampere to be slow but M series to be fast?

Apple design their own Arm-compatible cores from scratch. Ampere use a modified Arm Neoverse N1 core. In addition, the Ampere server that Marcin is using is about 6 years old, and would have been tuned for core count over single thread performance (good for web serving). Basically Arm's own cores aren't nearly as good as Apple's at the best of times, and having a 6 year old server makes things even worse.

Because they're designed for different things.

Ampere's primary focus is running lots of simple tasks concurrently, at relatively low power, with lots of I/O. So, many tens to hundreds of cores, not too fast, at lower power draw than amd64, with lots of PCIe lanes for storage and network.

Apple's primary focus is user experience and power efficiency. That's why you'll find a handful of fast performance cores and low power efficiency cores, along with graphics acceleration to drive high resolution displays.

Benchmarks are easy to find. The basic M1 has double the single core performance over the Ampere Altra Max: https://www.cpubenchmark.net/compare/6915vs4104/Ampere-Altra...

To expand on what others have said, aarch64 merely defines the set of instructions that the CPU can perform. That has an impact on how you design processors, but you can still design multiple completely different processor architectures with different performance characteristics that all implement the aarch64 instruction set.

Ampere Altra is for cloud/datacenters/servers where multithreaded throughput is approximately all that matters. Apple M series is for consumers.