Master Roshi and Krillin had whole fight scene, conversation, rock paper scissors game, spitting, thinking and krillins fall in 1 second. Normally normal humans were unable to see them, and Roshi didn't even went all out yet.
he was also fast enough to after being shot at, to turn around and catch all 9 bullets or to wave his hand so fast it created a wind so strong it blowed away a 70-80kg heavy superhuman and smashed him into a wall.
And kid Goku before drinking mystic water was so much faster that Roshi couldn't even see him.
Tien who was as fast as Goku (before water) was unable to touch fat demon, and Goku ( after water ) easily speed blitzed him.
After he drank that mystic water he become faster or as fast as young king Piccolo Doimao, who is incomparably faster then old one.
But even after drinking water and beating king Piccolo, Goku was still so slow that he couldn't even see mr. Popo. Mr Popo stated how he can move faster then lightning, and he was training goku so he could do the same.
As Popo stated Kami>>>>Mr. Popo, and Goku and Piccolo were fighting so fast kami couldn't even see them