They are benchmarks on real hardware, and I tried to provide enough details so that anyone can reproduce them (but some of the benchmarks are on servers I have that you can't order on public cloud -- these ones are clearly marked). "Synthetic" means that the data is synthetic, not an actual production workload. For instance, some of the benchmarks use files filled with random bytes.

So real benchmarks with synthetic data.

Do non-randomly ordered bytes produce different results??