How did you measure CPU performance? With DO you have propably a high "burst" cpu performance but if you keep using a lot of CPU ressources they will probably supsense your VM because of "abuse" or something (my experience with other VM providers). On Scaleway you have worse CPU performance but you can use the full CPU 24/7.
Compiling software is a somewhat meaningful metric across architectures (with caveats), but openssl speed is not really indicative of the CPU performance, rather it's benchmarking its own fast assembly routines. That only matters if your workload is crypto-bound.