The 4424, like our other scopes, switches automatically between block mode and streaming at about 100mS/div time settings. The exact point of switching can be forced up or down in Tools/Preferences.
The sample rate and number of samples per channel is very dependant on the actual settings requested.
Figures below are for a request for maximum number of samples on a 4224 (using one channel) and using auto trigger. In this case half the buffer is used to display the last capture and half is used to buffer the new.
0.05 second screen time-80MS/sec-4.0MSamples
0.1 second screen time-80MS/sec-8.0MSamples
0.2 second screen time-80MS/sec-16.0MSamples
0.5 second screen time-20MS/sec-10MSamples
1 second screen time-10MS/sec-10MSamples
2 second screen time-6.67MS/sec-13.33MSamples
5 second screen time-3.33MS/sec-16.7MSamples
10 second screen time-1.67MS/sec-16.7MSamples
With 2 channels used, you can capture:-
0.1 second screen time-80MS/sec-8.0MSamples each channel
0.2 second screen time-40MS/sec-8.0MSamples each channel
In single shot mode, more of the buffer is available for a single channel:-
0.5 second screen time-40MS/sec-20MSamples