CPU load is between 30-40 usually so I guess it's fine.

Concerning the card that yields less Sols, I think it's cuz it's the first one, and it has something to do with Xorg running on it. At least on W10 it behaved the same when I had my monitor connected to it, instead of Intel gpu. Quite a few people complained about the same issue always being with the first card.

Also I noticed that after some time I start getting
msg buffer full
Why is that, is it hurting me somehow?