Just got a new ASI174mm and it only can reach 62fps mono16 & 90 fps mono8; they should be 128fps & 164fps. Varied Turbo USB and fastest setting turbo USB was 80. A friend had the same issue with their ASI178mm. I ran the 174 camera with various USB 3 cables and used ASICAP and SC with no change.
The ASI174 fps should be double the values I'm getting. My other ASI cameras all reach their maximum fps specs.