Redis actually has a surprising number of performance issues with larger data sizes. But most people use it with small value sizes and TCP performance dominates. I could write for hours on how bad Linux TCP/IP perf is with small packets but I'll save that for another time. This is the bottleneck with the benchmarks op has done here (the value size is only 3 bytes in these benchmarks).

Since we're sharing Redis clones, here's my multithreaded one: https://github.com/JohnSully/KeyDB