Ok, I will benchmark this more when I have time. My gut feeling is that it is impossible to reach OpenBLAS-like performance without carefully tuned kernels and

Ok, I will benchmark this more when I have time. My gut feeling is that it is impossible to reach OpenBLAS-like performance without carefully tuned kernels and without explicit SIMD code. Clearly, it's not impossible to be as fast as OpenBLAS otherwise OpenBLAS itself woudln't be that fast, but it is very difficult and takes a lot of work. There is a reason much of OpenBLAS is implemented in assembly and not C.