Memory, Throttling Benchmarks
I also wanted to show memory bandwidth here, as the Ryzen 5 2500U supports DDR4-2400 and pushes higher bandwidth than the Kaby Lake-R Core i7-8550U. Clearly we are not memory bandwidth limited in the benchmarks I’ve just been showing.
While AMD lists the maximum boost clock of the Ryzen 5 2500U as 3.6 GHz, the CPU does not hit this clock speed under sustained workloads to keep within the TDP, which is common behaviour. With the Core i7-8550U, we saw sustained clock speeds during Cinebench in the 2.6 to 2.7 GHz range on all cores despite a maximum all-core turbo frequency of 3.7 GHz. With a single thread though, the 8550U hit 3.7 GHz in a sustained workload.
It’s a similar story with the Ryzen 5 2500U, in fact this APU varies on a per-core basis more frequently than Kaby Lake R. However, I did see consistent performance around 2.7 to 3.0 GHz on all four cores, while on a single core, the 2500U has no trouble hitting 3.6 GHz consistently. This gives the 2500U a clock speed advantage in multi-threaded workloads, and a small disadvantage in single-core loads.