How do I control the x scale and still have it update

I’ve noticed that when I change the x-scale the quad stops updating as quickly. Example: I am inputing a 5v 20 HZ sine wave. At 5us if I connect the quad I nearly immediately see the sine wave. However, the time step is too small to see the full cycle. If I change the x scale (orange) from 5 us to 1s it takes about 63 seconds from the time I connect the leads to the time that I see the sine wave. Furthermore during this time It claims that it is refreshing at a whopping 68 fps!

at 100ms it takes 8 seconds.

Simple mathematics
1s per div. If you move the display using XPOS you count around 130 div in the all buffer.
So before displaying you should fill 130s of data.

Ok so I guess the question I should’ve asked is how do you change the buffer length?