I've finally ran SSL server test on my server and was presented with:

> This server supports weak Diffie-Hellman (DH) key exchange parameters. Grade capped to B.

So I tried to generate stronger using `openssl dhparam 8196`, but it didn't finished even after a day. So, two questions:

1. Is it an overkill and is 4096 sufficient for now?

2. Can I make `openssl dhparam` run on multiple cores?