DHOXXXX also has it and call it Record mode. And it seems Record mode works similar to other scopes segmented mode. You can analyse data (search, view, decode... from it etc.) acquired in Record mode. I haven't used it but from what I can see it seems to work in adequate manner.
But this UltraAcq mode is separate from that and has these few visual representations and nothing else. You cannot measure, or do anything with data. It is similar to DPO mode in old Tektronix scopes (like old TDS754), where when you enable it all other functions are disabled. It triggers faster but you can only look at the waveform on the screen.
Do we know whether "UltraAcquire" actually triggers faster than regular "Record" mode in the DHO series? Not sure why it would be able to do that, from a technical perspective. But if that were indeed the case, the only reason for UltraAcquire's existence might be to have a faster waveform update rate in the spec sheet?
It does. Martin did some tests. Fact is Rigol does not usually lie with the facts. What they do is they twist what they mean and what is usability of it.
I personally think "bragging rights" to claim fast wfm/s is the only practical use of this mode at this moment.
In attachment a hard to find w.p. from Rigol that explains virtues of UltraAcq. It was written for big brothers 1000/4000.
It has 5 display modes:
1. Waterfall - Which is nothing like we call waterfall display on SA for instance. I fail to see how easy is to see some detail when everything is overlapping on same screen with same color.
2. Adjacent - Same as No.1 but horizontal shift instead of vertical. Even worse to grasp what is going on here.
3. Perspective - Ok, this looks similar to 3D surface plot, but badly looking. Gaps are too wide and no removal of hidden lines. No rotation?
4. Overlay - OK that one I get. And every scope with segments has this one. Useful.
5. Mosaic - I understand what is it. I have no use for it for practical work. Maybe some documentation? But has no connection to needing super fast WFMS/s for this. This could have been added to normal segmented mode as display mode. All of these could have.
What is not there: any type of scales, time stamps, info. There are no measurements, cursors, search, math, nothing.
Even if you see some anomaly you won't know when it happened. OK, if it repeats on screen you could see how it repeats in relative terms, but without any data, you don't know frequency, timing. Nothing. If there is a voltage drop in there, you cannot measure it...
It is literally empty screen with bunch of wiggles on it.
In Overlay mode it is similar to DPO mode in old Tektronix scopes (for instance old TDS754). Minus intensity/color grading.
I guess in Overlay mode it could be used to catch some glitches faster than in normal mode.
It will give you information that something was there if you put it in Overlay mode and look for an anomaly, visually.
And then with that knowledge you design series of triggers to catch those in a way that will give you some actual information about it.
Which is something you can do on a many scopes out there in persistence mode... But those can do all the other things FastAcq cannot. And those are very useful.
Getting wfm/s in this way is very limited in it's usefulness.
For instance, champion of wfm/s, Keysight Megazoom scopes, can reach 1M wfm/s in normal mode at certain time bases. And do all the normal functions at the same time. So you do measurements and gather statistics at very fast rate.
With this FastAcq you cannot do ANY of that.
In normal mode you are actually slower than some competition that can do "only" 120k wfm/s. Because in normal mode DHO800 can do only 30k wfm/s.