First oscilloscope: DS2072A or DS1047Z?

[sgofferj]

Hi,

I have read the "Newbie read here first" post. I have searched plus skimmed about 30 or 40 pages manually but I didn't find an answer to my question. If there is one which I missed, feel free to shout at me!

Here is the deal: I'm more or less an electronics hobbyist. I tinker a lot, mostly digital, i.e. Arduino & similar. I recently started doing some more "professional" development of some open source software and hardware and I feel that I should have an oscilloscope. The last 4 or so weeks, I have been googling, watching Youtube videos, etc...
I was fairly sure that I want to buy a Rigol DS2072A and asked the Finnish dealer for a quote. They said, it's not on stock and it would take long to get but they have the DS1047Z on stock and it would be cheaper and maybe better suited for my needs.
So I have read about the DS1047Z - and read about 1/3 of the Rigol megathread (reading backwards)...

And I have no idea what I should buy now... I'm just not deep enough in the topic. What I'm sure of is that I want to buy something that I can use for a few years, i.e. I don't want to "outgrow" it in a couple of months. I think, the main question for me is - for my purposes - do I rather have 4 channels (DS1000Z) or 300MHz (DS2000A)? Will the 100MHz of the DS1000Z series be enough for my future needs?

Basically, I'm looking for opinions of people who are standing where I will (hopefully) be in a few years...

-Stefan

[dp]

What I'm sure of is that I want to buy something that I can use for a few years, i.e. I don't want to "outgrow" it in a couple of months. I think, the main question for me is - for my purposes - do I rather have 4 channels (DS1000Z) or 300MHz (DS2000A)? Will the 100MHz of the DS1000Z series be enough for my future needs?

I can see some confusion here. First, it's DS1074Z and not DS1047Z. Then, both 2072A and 1074Z are 70 MHz scopes (that's the meaning of the 07 in their names). So, you have to choose between the 4 channels of one and the better functionality of the other. But this is a choice that only you can make. You're not likely to outgrow any of them in a matter of months.

[nctnico]

Did you look at the Siglent SDS2000 series? 4 channels and twice the samplerate the DS1000Z series has.

[tautech]

Did you look at the Siglent SDS2000 series? 4 channels and twice the samplerate the DS1000Z series has.

Siglent SDS2074 RRP US$1168 plus taxes if any

[sgofferj]

I can see some confusion here. First, it's DS1074Z and not DS1047Z. Then, both 2072A and 1074Z are 70 MHz scopes (that's the meaning of the 07 in their names). So, you have to choose between the 4 channels of one and the better functionality of the other. But this is a choice that only you can make. You're not likely to outgrow any of them in a matter of months.

Whoops, typo. Could you elaborate on the better functionality? I am still searching for a good YT video detailing the 1074Z. As I wrote, I don't really understand that much about DSOs. I have learned 25 years ago on analog scopes .

Did you look at the Siglent SDS2000 series? 4 channels and twice the samplerate the DS1000Z series has.

No, I haven't seen those yet. Unfortunately, also almost twice the price. I try to stay below €850 (soft limit ) or €1000 (hard limit). There would have to be a real valid reason for me to go over the "hobbyist budget".

[nuno]

Looks like you're so green you don't really know what you want/need. I would say, buy one of the older and much cheaper models DS1052E or DS1102E, use it and abuse it; when you have more experience you'll then know what you'll want.

[sgofferj]

That's exactly what I don't want to do - buy stuff that's within my personal capabilities and then buy new stuff every couple of months because I can't use the old one any more.
Besides, those old things lack some functions that I actually do need, e.g. protocol analyzers.

[tautech]

And I have no idea what I should buy now... I'm just not deep enough in the topic. What I'm sure of is that I want to buy something that I can use for a few years, i.e. I don't want to "outgrow" it in a couple of months. I think, the main question for me is - for my purposes - do I rather have 4 channels (DS1000Z) or 300MHz (DS2000A)? Will the 100MHz of the DS1000Z series be enough for my future needs?

Future needs is the key.

Up to 100 MHz is all most hobbyists require.
 
Having 4 channels is underestimated feature. Essentially a poor mans LA. Also can be configured for 2 channels of differential input use.

Future capability requirements like decoding, AWG, MSO etc.
Not something you may need right now but if a scope has these add ons it is more attractive IMO.
Much cheaper to add these later than replace your DSO.
Siglent comes with options enabled for the first 30 power cycles for your appraisal.

[rob77]

if you don't know what you'll need in the near future, then go for a cheaper 1xxx series - basically all those cheap scopes are the same, just the case, color and the software is different rigol, owon, hantek - it's all the same.

if you're doing digital then go for the 100Mhz bandwidth (or higher) and sample rate 1GSa/s (2x 500MSa/s for dual channel). the prices are approx 400-500Eur for the 2x100Mhz models. of course those are older models with less features and lower waveforms per second.. but they will do the job for you. (i'm using one of those older models - Hantek DSO1102B)
such a DSO will serve you well in the next 1-2 years... and afterwards you'll know what you need and which one to buy as your next DSO , or you'll just figure out that you don't need a new one

[tautech]

Just noticed your flag.
Search members for rf_loop. He also is in Finland and can supply you locally from his range of equipment.

[Strada916]

I have been a hobbyist for almost 32 years (started when I was I have just purchased my first DSO. I ended up with the DS1074SZ as I thought the 4 channels and frequency generator was the breaker. The DS2072 was my first choice but then the DS1074SZ came out and it had all the features I wanted. So ended up with that. Did some additional reading and added some additional features    . Very happy with unit now. Good luck with what ever you choose.

[nuno]

That's exactly what I don't want to do - buy stuff that's within my personal capabilities and then buy new stuff every couple of months because I can't use the old one any more.
Besides, those old things lack some functions that I actually do need, e.g. protocol analyzers.

Uau, every couple of months, man, you're a fast learner . You have to pay extra ~160€ for the RS232, I²C and SPI analyzers on the Rigol 1000Z series, on the DS2000A series ~220€ for the same + ~220€ just for CAN, only the "parallel" decoding is included in the base models - if what you really need is protocol analyzers you should probably take a look at logic analyzers. Anyways, you will regret more having spent 1000€ when you discover that what you needed was the other 1000€ scope **. You'll take your time learning about and discovering what a scope can do. Did you know that under certain circumstances the 2 channel Rigol (even the now <300€ shipped DS1052E I have on my bench, other brands too probably) is actually a 3 channel scope? We learn these little things over time and get more and more from the same scope, and it ends up serving us for longer and making us learn much more.

** or the 500€ scope plus the 500€ logic analyzer

[olewales]

I have the exact same problem. I am mostly playing with digital stuff and while I honestly probably don't NEED an oscilloscope I really WANT one because when I occasionally deal with stuff like signal integrity problems I don't have a tool for the job. I have pretty much decided on buying Rigol because they are reasonably priced and in my opinion engineered better than other brands aiming at this market segment. Community support and potential hackability is also a factor. I've ruled out DS1052E since I saw Dave's review of DS2000 series. I love high update rate and intensity grading of those new devices and I think I could make use of this. Then the DS1000Z series came out and since then I cannot decide on one or another. It seems like a great device with 4 channels and at least 100Mhz bandwidth (single channel, afair some people measured >150Mhz) and its considerably cheaper than DS2000! Feature-wise it seems not much different but for some reason people don't seem to like it very much. I've seen quite a few recommendations of DS2000 "unless you really need 4 channels". Why?! Is it the front end? Is it the controls? Is it the on-board software? Does it run slower? So far I haven't seen side by side comparison between the two on a video (except for intensity grading comparison) which would clearly show how those units perform in exact same conditions. mjlorton mentioned in his DS2000 series review that he is getting DS1000Z and I am very much looking forward to this.

Dave! It's not too late to do a "quick" comparison between DS1000Z and DS2000 on a video. I am sure that some Rigol distributor would happily lend you one.

[PedroDaGr8]

IIRC, the biggest drawback of the DS1074Z is that the sample rate is shared across all four channels. Do if you are using four channels your max sample rate per channel is 250MSa/sec. It also has a slower processor and for certain features that shows.

[marshallh]

If you're doing any digital, you need all the bandwidth you need.. 300mhz is barely scratching the surface here

[rob77]

If you're doing any digital, you need all the bandwidth you need.. 300mhz is barely scratching the surface here

that's true, but a "hobbyist digital" is not so critical - you can get along with the 100Mhz bandwidth - if you are aware off all the distortion your limited bandwidth introduces.
i'm doing lot of digital - but using a 2x100Mhz scope (hantek) and a logic probe with integrated 12 bit counter with leds (my own design - you have to "read" binary , but that's o.k. for me ). that probe gives me a lot of help (in some cases more help than the scope).

[sgofferj]

I have been a hobbyist for almost 32 years (started when I was I have just purchased my first DSO. I ended up with the DS1074SZ as I thought the 4 channels and frequency generator was the breaker. The DS2072 was my first choice but then the DS1074SZ came out and it had all the features I wanted. So ended up with that. Did some additional reading and added some additional features    . Very happy with unit now. Good luck with what ever you choose.

That was pretty much the kind of feedback I was looking for . Thanks!
How happy are you with the UI? I heard/read/saw that it tends to lag badly. Is it tolerable?

[Strada916]

To tell you the truth I'm still learning it's features and find it ok for what I do. The ds2000 series is the better scope if you can afford it. You can add the other features as you go if you know what I mean. ??

[sgofferj]

To tell you the truth I'm still learning it's features and find it ok for what I do. The ds2000 series is the better scope if you can afford it. You can add the other features as you go if you know what I mean. ??

Yeah, I have read a lot of the respective threads . I'm aware of the riglol software . I wonder if that works for the 1074Z-S too...

So - you haven't found anything vastly negative yet, like lockups of the screen or something like that? I have to admit that I tend to run circles under the ceiling pretty quickly if I can't go my pace because some UI lags or something like that...

I have done some more research and from what it looks like, 100MHz is all I will need and having 4 channels vs. 2 should be a real advantage. I wrote in my introduction that I tinker a lot with µCs, mainly Arduino and I recently do a lot of UAV-stuff and now I'm ready to step up my game a bit, development-wise. But I'm not going to go full-size PC or so - I'll stay with µCs. And at least the developers of the Ardupilot-project which I asked, said that I probably won't need 300MHz bw but the 4 channels will come in handy and so would the AWG.

[rob77]

 I have to admit that I tend to run circles under the ceiling pretty quickly if I can't go my pace because some UI lags or something like that...

then definitely go for the newer and faster DSO.. the older DSOs 1xxx are pretty slow and laggy when capturing with long mem at max sampling rate - you would run your circles on the ceiling quite often

[Fagear]

I've made my comparison between DS1000Z and DS2000A (Warning! Russian voiceover and text!):
? ?? Rigol DS1000Z ? DS2000A

Main differences:
1) screen size: 7" (175 mm) vs 8" (200 mm); waveforms region: 115x75 mm (12x8 divs) vs. 155x85 mm (14x8 divs); X-Y: 45x44 mm vs. 80x75 mm.
2) menus on DS1000Z can not be hidden.
3) DS1000Z: 4 channels, 1 MOhm; DS2000A: 2 channels, 1 MOhm/50 Ohm.
4) no RTC in DS1000Z (in DS2000A time/date can be saved within screenshots and it is displayed as tag on frames of segmented memory).
5) DS1000Z: 1 GSa/s @ 1 channel, 500 MSa/s @ 2 channels, 250 MSa/s @ 3 or 4 channels; DS2000A: 2 GSa/s @ 1 channel, 1 GSa/s @ 2 channels.
6) DS1000Z: 12 Mpts (24 Mpts opt.); DS2000A: 14 Mpts (56 Mpts opt.).
7) DS1000Z: up to 30000 wfs/s (claimed), up to 63000 wfs/s (!!! ) (measured); DS2000A: up to 50000 wfs/s (claimed), up to 53000 wfs/s (measured).
DS1000Z: only coarse steps while changing horizontal scale; DS2000A: coarse or fine adjustment of horizontal scale.
9) DS1000Z: horizontal scale reference point: only center of the screen; DS2000A: horizontal scale reference point: center of the screen, trigger point, user-set point on the screen (it can make big difference in usage of the DSO).
10) DS1000Z: segmented memory is option, no "analyse" and "open" (FIFO) mode; DS2000A: stock function, "analyse" mode and two recording modes: "record" (first N captures) and "open" (last N captures).
11) DS1000Z: very poor decoders, decoding works on display memory; DS2000A: decoding works on sample memory (when edges on the screen are washed out decoder on the DS1000Z stops or shows corrupted data... with RS232/I2C if there is not "start" condition on the screen - decoder shows corrupted data/completely stops... no matter what is in the sample memory and how delayed sweep is used).
12) DS1000Z: 90,5 MB internal storage; DS2000A: 64 kB internal storage. 

[tom66]

I've been a little annoyed by how the DS1000Z does serial decode, but it's pretty useful once you get around the screen depth limitation.

[Dave Turner]

I suggest that you search this blog as there are a number of threads on this subject.

For me, on a limited budget, the extra 2 channels were of more value. With a larger budget I'd be looking at different set of models/manufacturers, but I'd still be looking at 4 channel scopes.

[David Hess]

There is more to fast oscilloscopes than high bandwidth.  Above about 100 MHz probing becomes increasingly tricky and expensive.  A 100 MHz oscilloscope will not show edges faster than 3.5 nanoseconds but it can measure delay between them much smaller than that.  If you are relying on 300 MHz performance and still using a ground lead then the extra bandwidth you paid for is just serving to mislead.  (Haha, mislead . . .  never mind.)

Most applications can get by with just two channels if a separate trigger channel is available at the cost of some time so I would get the less expensive oscilloscope unless you have a specific need for 4 channels.

The two things I absolutely would require on a new DSO are intensity grading on the display and peak detection which I believe both of those oscilloscopes support.

[nuno]

If you are relying on 300 MHz performance and still using a ground lead then the extra bandwidth you paid for is just serving to mislead.  (Haha, mislead . . .  never mind.)

I'm not an expert but I don't think you have to reach 300MHz, I already have "stuff" in my 50MHz scope when using the ground lead .

[edavid]

Most applications can get by with just two channels if a separate trigger channel is available at the cost of some time so I would get the less expensive oscilloscope unless you have a specific need for 4 channels.

In this case the less expensive oscilloscope (DS1074Z) is the one with 4 channels 

[David Hess]

If you are relying on 300 MHz performance and still using a ground lead then the extra bandwidth you paid for is just serving to mislead.  (Haha, mislead . . .  never mind.)

I'm not an expert but I don't think you have to reach 300MHz, I already have "stuff" in my 50MHz scope when using the ground lead .

If your ground lead is long enough or there is enough flux leakage around the probe, lower frequencies can be a problem.  When I probe off-line power supplies, I get the best results using short lengths of thin coaxial cable soldered to the test points with coaxial connections to the x10 passive probes.  If I get really desperate, then I do the same thing differentially.

As a practical matter, my 300 MHz DSO is useless at high sensitivity settings with a fast passive probe and any ground lead because of local EMI.

[sgofferj]

I have been thinking quite a bit about this and I got some valuable input from this thread. As I'm mostly digital and from what I plan to do, there will likely be quite a bit of protocol analyzing involved, reliable analyzing will be important for me. On the other hand, I'm probably not going to need 4 analog channels.

Bottom line, I'm currently strongly leaning towards the MSO2072A, maybe MSO2072A-S.

[tautech]

I have been thinking quite a bit about this and I got some valuable input from this thread. As I'm mostly digital and from what I plan to do, there will likely be quite a bit of protocol analyzing involved, reliable analyzing will be important for me. On the other hand, I'm probably not going to need 4 analog channels.

Bottom line, I'm currently strongly leaning towards the MSO2072A, maybe MSO2072A-S.

https://www.eevblog.com/forum/testgear/siglent's-new-product-msosds2000-series/msg466708/#msg466708

Some comments  that may be pertinent.

[marmad]

7) DS1000Z: up to 30000 wfs/s (claimed), up to 63000 wfs/s (!!! ) (measured); DS2000A: up to 50000 wfs/s (claimed), up to 53000 wfs/s (measured).

Fagear - I watched your video, but I couldn't understand how you thought you were measuring waveform update rates. Granted, I don't speak Russian, so I could be misunderstanding something, but I didn't see any valid method of measuring. For example, at 8:53 you have the DS2000 set to 10us/div with the frequency counter showing ~54kHz while running on AUTO trigger. Did you believe that was showing that the DSO is capturing ~54000 waveforms a second? Well, it's not - as you can check with simple math:

At 10us/div (and memdepth <= screen size), it takes 140us to capture the full waveform for display (10us * 14 divs). That means the absolute maximum waveforms that ANY DSO could theoretically capture in that time would be 7142 (1/140us) - and that would be with ZERO blind time (in other words, impossible).

The DS2000 actually captures ~1000 wfrm/s @ 10us/div. See my waveform update rate chart down towards the bottom of this message. The maximum rate I've measured on the DS2000 is 52770 wfrm/s using DOTS mode @ 20ns/div - and I don't think the DS1000Z gets close to this.

Valid waveform update rates can not be measured while using the AUTO trigger - and if you're going to use the frequency counter on the DSO, you have to loop the Trigger Out back into the DSO on another channel (or External Trigger In).

12) DS1000Z: 90,5 MB internal storage; DS2000A: 64 kB internal storage.

Where did you get these numbers from? Are they published somewhere?

[Fagear]

Fagear - I watched your video, but I couldn't understand how you thought you were measuring waveform update rates. Granted, I don't speak Russian, so I could be misunderstanding something, but I didn't see any valid method of measuring.

I've answered on Youtube, but I'll do it here as well.
On 8:52 my DS2072A is measuring trigger output of the DS1104Z, not itself. So 54 kHz on hardware counter - it is waveform update rate of the DS1104Z. And if you can see later, on-screen measurements show 63 kHz between pulses. Hardware counter shows less because DS1000Z has pause in processing (10:22). "Sweet spot" settings for DS1000Z I have found: 50 ns/div, dots, auto memory.
On 12:02 the DS1104Z shows trigger output signal of my DS2072A. And "sweet spot" is 20 ns/div, dots, auto memory. So the result is ~53 kHz as you have measured.

Both DSOs are fed with 20 MHz sine wave.

So... yeah. It's very strange but DS1000Z outperforms DS2000A!?

Where did you get these numbers from? Are they published somewhere?

Just "Storage -> Disk.Manage".

[marmad]

I've answered on Youtube, but I'll do it here as well.
On 8:52 my DS2072A is measuring trigger output of the DS1104Z, not itself. So 54 kHz on hardware counter - it is waveform update rate of the DS1104Z. And if you can see later, on-screen measurements show 63 kHz between pulses. Hardware counter show less because DS1000Z has pause in processing (10:22). "Sweep spot" settings for DS1000Z I have found: 50 ns/div, dots, auto memory.
On 12:02 the DS1104Z shows trigger output signal of my DS2072A. And "sweep spot" is 20 ns/div, dots, auto memory. So the result is ~53 kHz as you have measured.

Both DSOs are fed with 20 MHz sine wave.

So... yeah. It's very strange but DS1000Z outperforms DS2000A!?

Thanks. I also answered you at YouTube, but I'll re-post here for others:

Ahh... that explains it! Sorry for my misunderstanding - one of the problems with not knowing the language I thought I had read somewhere else that a DS1000Z owner had measured the wfrm/s and never found a higher rate than ~30k, but perhaps he didn't try Dots mode. But it makes me wonder why Rigol doesn't advertise it as ~50k wfrm/s DSO?

Just "Storage -> Disk.Manage".

Ok, thanks!


EDIT: It would be handy if a DS1000Z owner would create a chart with wfrm/s speeds for all time bases, with Dots / Vectors / Sin(x).

[marmad]

So... yeah. It's very strange but DS1000Z outperforms DS2000A!?

The wfrm/s rates also seem to be fairly changeable from version to version of the firmware, at least for the DS2000. I haven't re-measured the DS2000 since FW v.3 came out, but you can see by the attached chart, some of the time base wfrm/s rates changed quite a bit from FW v.1 to v.2.

[Fagear]

a DS1000Z owner had measured the wfrm/s and never found a higher rate than ~30k, but perhaps he didn't try Dots mode

In my review of the DS1104Z-S I've showed some other measurements:
for auto, vectors:
100 ns/div = 13 kHz
50 ns/div = 22 kHz
20 ns/div = 22 kHz
10 ns/div = 20 kHz
5 ns/div = 15 kHz

dots:
50 ns/div = 53 kHz
20 ns/div = 25 kHz
10 ns/div = 25 kHz
5 ns/div = 20 kHz

Actually, I've reflashed DS1104Z to the latest FW (00.04.00.00.00, 2014-03-18) before tests.

EDIT: It would be handy if a DS1000Z owner would create a chart with wfrm/s speeds for all time bases, with Dots / Vectors / Sin(x).

Maybe I can do it. Just have to find some time for it. But how I should perform these measurements? Includind 7 ms pause in capturing (while there no impulses at all and top frequency equals 54 kHz) or without that pause, simply time between impulses (63 kHz)?

[marmad]

dots:
50 ns/div = 53 kHz
20 ns/div = 25 kHz
10 ns/div = 25 kHz
5 ns/div = 20 kHz

Actually, I've reflashed DS1104Z to the latest FW (00.04.00.00.00, 2014-03-18) before tests.

I think I understand now why Rigol marketed it as ~30k wfrm/s DSO: because in original FW, that was the highest speed they could achieve at the time it was introduced. But they've optimized the code since and, just like the DS2000, they've been able to get higher speeds at the 50ns/div (and perhaps other) time base(s).

Maybe I can do it. Just have to find some time for it. But how I should perform these measurements? Includind 7 ms pause in capturing (while there no impulses at all and top frequency equals 54 kHz) or without that pause, simply time between impulses (63 kHz)?

I think you have to include the pause - since the DSO is not capturing waveforms then - so that is the real 'effective' rate.

[rf-loop]

dots:
50 ns/div = 53 kHz
20 ns/div = 25 kHz
10 ns/div = 25 kHz
5 ns/div = 20 kHz

Actually, I've reflashed DS1104Z to the latest FW (00.04.00.00.00, 2014-03-18) before tests.

I think I understand now why Rigol marketed it as ~30k wfrm/s DSO: because in original FW, that was the highest speed they could achieve at the time it was introduced. But they've optimized the code since and, just like the DS2000, they've been able to get higher speeds at the 50ns/div (and perhaps other) time base(s).

Maybe I can do it. Just have to find some time for it. But how I should perform these measurements? Includind 7 ms pause in capturing (while there no impulses at all and top frequency equals 54 kHz) or without that pause, simply time between impulses (63 kHz)?

I think you have to include the pause - since the DSO is not capturing waveforms then - so that is the real 'effective' rate.

I recommend that use example 1 second average (1 second gate time if use  conventional pulse counting principle working frequency counter. ) for fast time/div settings. If want measure slow timebases then need example 10s gate time. 

If we measure very short time peak speeds it may lead to situation where some scope with some settings may give unexpected and not useful fast peak rates.

[Fagear]

I haven't re-measured the DS2000 since FW v.3 came out

I've done all of the measurements and did not find any differences in wfs/s performance between FWs v.2 and v.3.
Here is the comparison:


More details about performance of FW 00.03.00.01.03:


I've also have similar data for the DS1000Z series:



And comparison DS1000Z vs DS2000A up to the limits:


Found some interesting details: DS2000A has enough power to process all data:


But DS1000Z feels to be limited, it goes to full memory only after some steps of sampling speed:


Overlay comparison:

[marmad]

I've done all of the measurements and did not find any differences in wfs/s performance between FWs v.2 and v.3.

Nice! Very thorough - thanks for doing these!

[tom66]

Your comparison of memory length vs sampling rate is inaccurate on the DS1000Z. The auto mode does have those selections, but in all memory lengths you can get 1GSa/s, regardless of timebase. It's only when the distance between the points is less than about 1ns (1GSa/s) does the memory depth drop.

[marmad]

Your comparison of memory length vs sampling rate is inaccurate on the DS1000Z. The auto mode does have those selections, but in all memory lengths you can get 1GSa/s, regardless of timebase. It's only when the distance between the points is less than about 1ns (1GSa/s) does the memory depth drop.

Tom - can you be more specific about which chart you mean? As far as I can tell, all of his charts are focused exclusively on measuring the AUTO mode (so memory length would be set automatically), except for #3 - and that one isn't dealing with the sampling rate. So I'm confused.

[tom66]

Your comparison of memory length vs sampling rate is inaccurate on the DS1000Z. The auto mode does have those selections, but in all memory lengths you can get 1GSa/s, regardless of timebase. It's only when the distance between the points is less than about 1ns (1GSa/s) does the memory depth drop.

Tom - can you be more specific about which chart you mean? As far as I can tell, all of his charts are focused exclusively on measuring the AUTO mode (so memory length would be set automatically), except for #3 - and that one isn't dealing with the sampling rate. So I'm confused.

He is using Auto mode but the chart is making it seem like those are the limits when they aren't. You can get 12Mpt or 24Mpt (licensed or hacked) at all timebases except where there isn't enough data to acquire (below about 20ns/div.) The auto mode just selects (presumably) the best memory depth and sample rate for high wfms/s or better intensity grading but you're free to get maximum memory in virtually all timebases. I've noticed a significant drop in wfm/s from 12->24Mpts, so I only use 24Mpts if absolutely required.

Not sure why it jumps to 7.5Mpts for only 5ms/div - it seems a little odd.

[marmad]

He is using Auto mode but the chart is making it seem like those are the limits when they aren't. You can get 12Mpt or 24Mpt (licensed or hacked) at all timebases except where there isn't enough data to acquire (below about 20ns/div.) The auto mode just selects (presumably) the best memory depth and sample rate for high wfms/s or better intensity grading but you're free to get maximum memory in virtually all timebases. I've noticed a significant drop in wfm/s from 12->24Mpts, so I only use 24Mpts if absolutely required.

I'm not sure the charts are making it seem that way. Chart #3 specifically shows other memory selections at all timebases - and chart #4 focuses on the AUTO setting - which, if it functions as it does on the DS2000, optimizes memory length to get, in order of priority:
1) the fastest sampling rate possible
2) the highest wfrm/s

You will always get the fastest sample rate possible at any timebase setting when using AUTO - but it doesn't mean, of course, that other memory depth settings aren't possible to achieve the same sample rate.