The AMD Ryzen 7 4800H is around 35% faster than the Intel Core i7-4800MQ at single-threaded workloads, up to being about 3× as fast when loading all cores (e.g. compiling code). I gather that the 5800H should be something like 25% faster again (~19% IPC improvement, 5–10% clock speed bump). Compared to the i7-4800MQ, that should be up to about 70% faster single-threaded, and 4× as fast with all cores loaded.

That’s H-class APUs, since you were talking about an Intel MQ. The U-class APUs seem to be surprisingly close in performance, mostly only 10–20% slower, with a third of the TDP.