is there a way to know what's the current speed of mining? I've set up a computer with 2 cards, both running 100% and the stats seem to be the same than when it was 1. But I can only seem to see stats after I get a payment, nothing during so I don't know if it has increased production.
Have you checked current mining pool's Dashboard?
Or worker page?
It's not perfectly same, but you can estimate the hashrate.