MSO vs MDO - What's going on?

[EEVblog]

That sounds like an interesting video! I'm surprised no other manufacturers seem to pursue a similar ASIC route even though they actually do roll their own ASICs. Rigol has just done one but achieved pretty much the opposite with a very sluggish MSO5000. It may be cheap but it's certainly not hardware accelerated to any similar degree.

And it doesn't have for some strange reason, HiRes capability. Crazy.

[EEVblog]

Not sure if the EEVblog admin is still looking at this thread but if so, I have a question.  When I was asking about "zone triggering" several posts back you said, "It's called "zone triggering" and the RTM3000 has it too. And yes, it's a real handy feature on modern touch screen scopes.".  I've just spent some time looking at the R&S website and as far as I can see, R&S doesn't offer "zone triggering" until you get to their RTO2000 model which starts at $14,000!!  Are you saying they've added it to the RTM3000 via a recent firmware update or something and just haven't updated their website (or it has an error)?  If so, that would be great!

Yeah, sorry, was searching a comparison datasheet, not an individual datasheet. RTO only it seems

[starlite4321]

Dang... Well, it seems like a lot of their competition does have it.  Maybe they'll add it in a future update.  It might turn out to be one of those things you think you'll use all the time but actually don't in the end.  All I know is out of about a zillion last second hardware nightmares in the dim past, one that still sticks in my mind would have been SO much easier to pin down if we'd had something like that back in the stone age.  R&S also has a whopper upgrade offer going and reviews of their stuff look pretty good.  Thanks again for the super fast response!

[Howardlong]

FWIW, Keysight are offering MSOX3104T fully loaded with probes, software options and a 1 year warranty for US$ 6848 in their ebay store at the moment. The only thing I'd recommend adding to the spec would be a LAN interface card.

https://www.ebay.com/itm/193024964977

The 3000T series offer both zone triggering and FFT gating (as well the usual Keysight Infiniivision slick UI, which to me is by far the most important feature!).

[EEVblog]

It seems only a matter of time before Keysight pushes out a new ASIC and owns the market for another 5 years. They've definitely had success with the current generation, so it surprises me no one else is going near it. Especially considering the sluggish nature of many UIs is a common complaint.

IIRC they averaged 8 years between Megazoom ASIC's and it's now been 10 years.
The two obvious things to improve are the memory size and the display resolution. I really hope they make it 1920x1080 capable with external HDMI support, that would be sweet. Internal screen doesn't have to do that, but better external resolution would be something no one else is doing.
They really don't have to improve much else, because 10 years later it still beats practically everyone else in hardware decoding and responsiveness.

[EEVblog]

Thanks tautech - those are great suggestions!  Do you have any experience with them?

Be aware that Tautech is a Siglent distributor, so he has a vested interest in talking up Siglent and does so at every opportunity on the forum, he's (in)famous for it.

[EEVblog]

Do you have any experience with these?  Do they have reasonably fast UI's for example?

Siglent UI responsiveness is very good, one of the better ones out there.

[EEVblog]

Tektronix has its own A/D chips, R&S has front end chips and A/Ds. It's just that Keysight had different priorities while designing it's architecture, putting responsiveness before everything, trying to make it feel analog like. Other manufacturers went for longer memories and other functions.

Actually, the Megazoom IV ASIC was released over 10 years ago now, and would have been developed for many years before that. Back then 4M of memory, especially fast integrated memory with hardware segmenting etc was a lot of memory. They owned the market when the 2000/3000 X series were released, no one else could touch it for a good 4-5 years. Now 10 years on the 4M looks small for sure, but it's still the fastest thing on the market. And that chip is built into their base model 1000X units, so at any time they can release a firmware upgrade and make a killer low end product.

[Mr. Scram]

FWIW, Keysight are offering MSOX3104T fully loaded with probes, software options and a 1 year warranty for US$ 6848 in their ebay store at the moment. The only thing I'd recommend adding to the spec would be a LAN interface card.

https://www.ebay.com/itm/193024964977

The 3000T series offer both zone triggering and FFT gating (as well the usual Keysight Infiniivision slick UI, which to me is by far the most important feature!).

Note that the offering is for used equipment and not what Keysight calls Premium Used. It's still a deal to consider, but it'd be good to confirm the equipment condition and warranty are what you're looking for.

[Mr. Scram]

Thanks tautech - those are great suggestions!  Do you have any experience with them?  I've got this basic "you get what you pay for" fear but I think it's not that simple anymore, at least for me for at least two reasons: 1) I can't AFFORD to just buy high end stuff and, 2) it's kind of a new world now where foreign companies can really compete with the big boys at significantly lower cost so it's at least possible to find "better" stuff for less money.  Especially for companies that have been at it for a long time, building up their repertoire.

Do you have any experience with these?  Do they have reasonably fast UI's for example?  The specs look pretty amazing given the price though I see the scope is still 8-bit.  I'm not hard over about that, it would just be nice if the design could support a lower noise floor and had the resolution to take advantage of it.  It looks like most things are 8 bit at this point so it's not like it's holding the world back or anything.

Along roughly similar lines, I just noticed the Rigol's have big free upgrade offers going.  In the case of the 7000 series scope, the upgrade is worth more than the damn scope!  Pretty amazing!

I will definitely look into these guys.  Again, thanks!

Chinese manufacturers have been steadily improving their act. Their support level still isn't on par with the higher end parties, though. Firmware support has been hit and miss and repair and parts availability shouldn't be relied on. If you're looking at the Chinese options you may want to look at the Rigol MSO5000 that was released recently. It's a mixed bag, they definitely have some firmware work ahead of them and the UI isn't as responsive as you'd like but with the non-manufacturer unlock it's a 350 MHz oscilloscope for under a $1000.

[Howardlong]

FWIW, Keysight are offering MSOX3104T fully loaded with probes, software options and a 1 year warranty for US$ 6848 in their ebay store at the moment. The only thing I'd recommend adding to the spec would be a LAN interface card.

https://www.ebay.com/itm/193024964977

The 3000T series offer both zone triggering and FFT gating (as well the usual Keysight Infiniivision slick UI, which to me is by far the most important feature!).

Note that the offering is for used equipment and not what Keysight calls Premium Used. It's still a deal to consider, but it'd be good to confirm the equipment condition and warranty are what you're looking for.

When I receive mine I'll report back ;-)

In the meantime I've been delighted with my MSO7104B for the past four years or so I've had it from the same source, which came without probes or warranty beyond the standard 30 days.

[Mr. Scram]

IIRC they averaged 8 years between Megazoom ASIC's and it's now been 10 years.
The two obvious things to improve are the memory size and the display resolution. I really hope they make it 1920x1080 capable with external HDMI support, that would be sweet. Internal screen doesn't have to do that, but better external resolution would be something no one else is doing.
They really don't have to improve much else, because 10 years later it still beats practisplay ally everyone else in hardware decoding and responsiveness.

I agree with the necessary display resolution and memory upgrade. The resolution really isn't bad but it's starting to lag behind the competition. It's mystifying how everyone cites the responsiveness of the Keysight and nobody else is even trying to copy it. I know it's not a big number on the specification sheet but it's obviously why many people like the oscilloscopes.


I know many other brands don't come anywhere near the listed waveform updates or only under very specific conditions. How's that with the Keysights? I think those are doing quite well in that regard?

[Fungus]

That sounds like an interesting video! I'm surprised no other manufacturers seem to pursue a similar ASIC route

It's very expensive to do.

Rigol has just done one but achieved pretty much the opposite with a very sluggish MSO5000. It may be cheap but it's certainly not hardware accelerated to any similar degree.

I think the Rigol ASIC is only for the front end, not the actual processing.

The "problem" the Rigol 5000 has is 400Mb of RAM (vs. 1Mb in the Keysight...)

The big advantage of the Rigol is that you can buy the $900 model and unlock all the features to get the $5000 model.

[rsjsouza]

IIRC they averaged 8 years between Megazoom ASIC's and it's now been 10 years.
The two obvious things to improve are the memory size and the display resolution. I really hope they make it 1920x1080 capable with external HDMI support, that would be sweet. Internal screen doesn't have to do that, but better external resolution would be something no one else is doing.
They really don't have to improve much else, because 10 years later it still beats practisplay ally everyone else in hardware decoding and responsiveness.

I agree with the necessary display resolution and memory upgrade. The resolution really isn't bad but it's starting to lag behind the competition. It's mystifying how everyone cites the responsiveness of the Keysight and nobody else is even trying to copy it. I know it's not a big number on the specification sheet but it's obviously why many people like the oscilloscopes.


I know many other brands don't come anywhere near the listed waveform updates or only under very specific conditions. How's that with the Keysights? I think those are doing quite well in that regard?

I think you answered yourself. The specification sheet will never be able to objectively state the amount of "responsiveness" of the UI - a key component when you are trying to go after the brochure/spec numbers game with your competitors.

It is easier and much more certain to throw more money (i.e., memory, GSPS, resolution, etc.) into the problem instead of making an expensive investment in a decent user interface that yields a more uncertain return.

Rigol has just done one but achieved pretty much the opposite with a very sluggish MSO5000. It may be cheap but it's certainly not hardware accelerated to any similar degree.

I think the Rigol ASIC is only for the front end, not the actual processing.

The Phoenix chipset seems to encompass a lot of other functions, including processing. 

[2N3055]

The Phoenix chipset seems to encompass a lot of other functions, including processing. 

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

[Mr. Scram]

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

It's probably pretty obvious what "scope responsiveness" means if you've ever used a Keysight. It's not just the UI. Turning on features means adding internal computations being done. Most of that is done in hardware on the Keysights, so there's no slowdown. Not just visually, but the actual work being done doesn't slow down either. The UI is also done in the MegaZoom IV ASIC, only some very specific things are done separately by the CPU. See page 4 of this document.

http://literature.cdn.keysight.com/litweb/pdf/5990-7906EN.pdf

[Mr. Scram]

I think you answered yourself. The specification sheet will never be able to objectively state the amount of "responsiveness" of the UI - a key component when you are trying to go after the brochure/spec numbers game with your competitors.

It is easier and much more certain to throw more money (i.e., memory, GSPS, resolution, etc.) into the problem instead of making an expensive investment in a decent user interface that yields a more uncertain return.

The Phoenix chipset seems to encompass a lot of other functions, including processing.

Sure it's not on the specifications sheet, but the one party doing it is definitely doing well.

[2N3055]

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

It's probably pretty obvious what "scope responsiveness" means if you've ever used a Keysight. It's not just the UI. Turning on features means adding internal computations being done. Most of that is done in hardware on the Keysights, so there's no slowdown. Not just visually, but the actual work being done doesn't slow down either. The UI is also done in the MegaZoom IV ASIC, only some very specific things are done separately by the CPU. See page 4 of this document.

http://literature.cdn.keysight.com/litweb/pdf/5990-7906EN.pdf

That is right. But pretty much all math and fft is done by accelerators in MSO5000. What is  slow is pretty much stupid U/I things, same as with R&S 3000. Sad part is that cheap tablets and phones are doing it much better and faster...
Siglent SDS5000X does it much, much better then the rest.

[rsjsouza]

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

I see several non-mainstream products using ready made windowing libraries (Qt, Android, etc.) that are  capable of delivering a decent UI on a regular applications processor (Cortex A). Given these oscilloscope chipsets already partition the system in a way to offload the number crunching away from the UI CPU, it should be a matter of directing resources to actually work on this aspect of the equipment. That is not cheap.

That is right. But pretty much all math and fft is done by accelerators in MSO5000. What is  slow is pretty much stupid U/I things, same as with R&S 3000.

Add the newest Tek 3 and 4 series there.

Sad part is that cheap tablets and phones are doing it much better and faster...

UI requires a reasonable amount of resources in the shape of developers and, most importantly, testers - but these are working for the lush green$ of the consumer industry... 

[egonotto]

Hello

EEVblog wrote: "It's called "zone triggering" and the RTM3000 has it too".

Are you sure? I don't find it in the datasheet and in the user manual. R&S says "zone trigger" is advanced and is only in RTO2000 and RTP (as an option)

Best regards
egonotto
 

[maginnovision]

No zone, just mask. Should usually be useful in same ways since it'll save fails in history. Or I don't know what people use zone trigger for, I've never used it even in scopes that had it.

[EEVblog]

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

It's probably pretty obvious what "scope responsiveness" means if you've ever used a Keysight. It's not just the UI. Turning on features means adding internal computations being done. Most of that is done in hardware on the Keysights, so there's no slowdown. Not just visually, but the actual work being done doesn't slow down either. The UI is also done in the MegaZoom IV ASIC, only some very specific things are done separately by the CPU. See page 4 of this document.

http://literature.cdn.keysight.com/litweb/pdf/5990-7906EN.pdf

Yes, and this why the 4000X series with it's much larger screen had to use the same 800x600 resolution as the small models, because all the screen stuff is mapped in the ASIC with a fixed resolution.

[David Hess]

Sad part is that cheap tablets and phones are doing it much better and faster...

I test them occasionally and have never found them to have good or even acceptable responsiveness.

The objective test is *maximum* latency between a command input and a result.  Given a 60 Hz display, anything up to 33 milliseconds is acceptable and they cannot even meet that.  Having the display pause while garbage collection or something is going on is particularly annoying.

[Howardlong]

That is correct. But problem is that many here are discussing "scope responsiveness" without explaining what it means.
Keysight 3000T has many things in hardware, but they "windows" part, the UI, is the one that is so fast.
Rigol MSO5000 has very fast acquisition engine (not as fast as Keysight but very fast), and even FFT and other things are not slow. What is slow is windowing interface, the UI.  You move something on the screen, it is slow. Same thing with R&S 3000, try scrolling horizontally with  a finger...

Where all these manufacturers are not doing very good job is in the UI. Most of them seem to use some ready made windowing library, that seems to be not very good choice for real time graphical instrument..

It's probably pretty obvious what "scope responsiveness" means if you've ever used a Keysight. It's not just the UI. Turning on features means adding internal computations being done. Most of that is done in hardware on the Keysights, so there's no slowdown. Not just visually, but the actual work being done doesn't slow down either. The UI is also done in the MegaZoom IV ASIC, only some very specific things are done separately by the CPU. See page 4 of this document.

http://literature.cdn.keysight.com/litweb/pdf/5990-7906EN.pdf

Yes, and this why the 4000X series with it's much larger screen had to use the same 800x600 resolution as the small models, because all the screen stuff is mapped in the ASIC with a fixed resolution.

Interestingly the previous Megazoom III used in the older generation 5000, 6000 and 7000 scopes supports XGA and 8Mpts, with a ~1000x640 pixel waveform area, almost the entire width of the display is used unlike the Megazoom IV which looks like a waveform area of about 640x384 pixels.

Megazoom III also supported 8Mpts compared to 4Mpts of Megazoom IV.

I’m not sure if this is ASIC dependent, but the digital channel sample rate of the older generation is 2Gsa/s compared to 1Gsa/s in the current generation of Infiniivision scopes.

[EEVblog]

Interestingly the previous Megazoom III used in the older generation 5000, 6000 and 7000 scopes supports XGA and 8Mpts, with a ~1000x640 pixel waveform area, almost the entire width of the display is used unlike the Megazoom IV which looks like a waveform area of about 640x384 pixels.
Megazoom III also supported 8Mpts compared to 4Mpts of Megazoom IV.

IIRC the Megazoom III used external memory. The IV 4Msamples is on the die, that's why it's so quick.