For a good example, what would the Agilent 3000 X-Series do? At 10ns/div, it's supposed to do 1,030,000 wfrm/s. But it can't possibly be acquiring the fixed memory size (1M) - it's impossible because (1 / 4G[Sa/s]) * 1M[Pts] * 1.03M[wfrms] = 257.5 seconds. In fact, it must only be acquiring a tiny subset of the full memory (possibly just the amount of samples for the display) -
1 * samples * wfms/s / samples/s = second ? i need koffee ^^At 4GS/s sample rate and 1Mpoint buffer depth the DSO need 250us to capture data into memory, then it need
to do the postprocessing. The total acquisition time is sum of both (i'm writing down all steps for those who get lost).
But total time is 1us (at 1M wfms/s), so the postprocessing need to be smaller than that, at least twice that small
(assuming Megazoom IV ASIC can do same data throughput during postprocessing). This give us 2000 data point per wfms.
Now let's calculate back, these 2000 points sampled with 4GS/s at 1M wfms/s give us then 0.5 which is less than
a second, which is what it should be because it need to be "per second".
The real data point value is probably equal to display resolution (visible area size, is it 600 dots?).
and only capturing the full length when STOP is pushed.
right, when writing once the full 1M buffer there is no blind time, so this part can work like that.
It can be as well as on TEK DPOs (not sure if on latest model as well), where the buffer is one time fully written
at begin of sampling (so when you do single shot it is once, and when you do RUN it is once ++++) and then
refreshed with what the hardware allows at max. (e.g. DPO3000 with 10k point, TDS700 with 500point)
When that's the case for Agilent, you would not even see (even with 4M memory) any gap between
"button pushed vs. data displayed", that' only 1ms to get full buffer once sampled, the refresh
data with 600-2000 dots per wfms is sufficient (as you can anyway see only that data and nothing else on screen).
So Rigol DS2000, with 21us total acquisition time from which 7us is used to capture the 14k points is not that bad,
that's (worst case) 7 time the buffer size of Agilent DSOX3000 (based on the findings/calculations above),
that's worst case third of DSOX 3000 wfms/s rate ^^ yeah, maybe.