Thoughts on MSOS104A vs HDO6104A-MS vs MSO56?

[Someone]

To me it seems like the S-Series does a lot of the processing on the ASIC.

Not sure where you get that idea from? Its an advertised feature on the V series, and the infiniivision scopes (they all have hardware serial triggers too) but never mentioned for the 9000/S-series.

[nctnico]

I'm still pondering if I need high update rates critically or not. I might not. Given the manufactures only really advertise the max rates, do folks know the rates as a function of what you are measuring well.

Update rates are way overhyped. In normal use case scenarios (with deep memory) the update rate is way lower than it says in the datasheet. It is a bit like a non-turbocharged car engine: the maximum power is available in a very narrow RPM range you rarely use in normal circumstances.

[Someone]

I'm still pondering if I need high update rates critically or not. I might not. Given the manufactures only really advertise the max rates, do folks know the rates as a function of what you are measuring well.

Update rates are way overhyped. In normal use case scenarios (with deep memory) the update rate is way lower than it says in the datasheet. It is a bit like a non-turbocharged car engine: the maximum power is available in a very narrow RPM range you rarely use in normal circumstances.

The peak rate is a good single figure which keeps marketing happy and says something about the capabilities of the scope, I've not found one yet that dropped away and increased blind time at longer record lengths so you can use it to estimate the performance across the range. R&S give peak rates at each memory depth to reassure the doubters but it may be in dot rendering mode as Keysight point out in their material to push the banner spec a little higher. Even the classic Tek DPO4000 kept close to the theoretical maximum rates across most of its range:

(dotted lines are aliased or record extending beyond the visible window)

[babryce]

I remember Shahriar Shahramian making the statement in his review of it, but is it true? (90+% sure if you watch the video he will say something like that around the time that he mentions the only connection is a PCI-E slot to the computer.

Is it true or speculation? I don't know. It is one lane of PCI-E but it could be any version of PCI-E, so the bandwidth is not known.

Also if anyone knows the ambient noise level of any of these scopes that would be nice to know also.

[Someone]

I remember Shahriar Shahramian making the statement in his review of it, but is it true? (90+% sure if you watch the video he will say something like that around the time that he mentions the only connection is a PCI-E slot to the computer.

Is it true or speculation? I don't know. It is one lane of PCI-E but it could be any version of PCI-E, so the bandwidth is not known.

You're throwing out a lot of "unknowns" here that can be checked and referenced...

Hardware-based algorithms for accelerated drawing to display (pixel placement) enable fast pan and zoom even with deep memory

The single acquisition board is a PCIe device attached to the motherboard with a PCIe extension cable. The x4 PCIe link includes nine differential pairs: four transmit pairs, four receive pairs, and one reference clock pair

But you're falling for the emotive marketing fluff which was repeated on The Signal Path rather than making measurable performance comparisons, the speed of display may be improved compared to other similar scopes but its far behind scopes which do the majority of the processing in an FPGA or ASIC.

Waveform update rate, Up to 2,000 wfms/s

Which doesn't specify the memory depth or sample rate at the time, for all their promoting of the "fast" display Keysight are very coy when it comes to providing details about the display rate of the S-seires which should be a big red flag when they so actively promote it on many of their other products. The limited speed is clear in The Signal Path video, and people on this forum have achieved similar (and even better) realtime performance from earlier acquisition boards rendering in software.

[babryce]

I continue to do research on this spec wise as my time allows.

I already saw the Tek/S comp with 2000 wfm/s, but thanks for putting it in the thread for others to look at.

The marketing materials of all vendors need healthy doses of salt given all the "*" I have found in the research I have been able to do.

[Keysight DanielBogdanoff]

I continue to do research on this spec wise as my time allows.

I'd highly encourage you to call our technical call line if you have questions. They are all engineers manning the phones and have a very deep technical knowledge. Phone number can be found here: http://www.keysight.com/find/contactus

I *think* you might want to start with the number in the "Support Specialists" tab. It's quick and free, and I even use it from time to time when I have a question.

The marketing materials of all vendors need healthy doses of salt given all the "*" I have found in the research I have been able to do.

To be perfectly honest, the "competitive comparison" type documents are not really made for engineers. They are made to help engineers convince managers and corporate purchasers. That being said, the lawyers go through that stuff with a fine tooth comb to make sure it's all technically accurate. It may be silly, but it's accurate 

[nctnico]

I wouldn't call it accurate. It is worded so that they can get away with it legally.

[Keysight DanielBogdanoff]

I wouldn't call it accurate. It is worded so that they can get away with it legally.

I guess what I'm trying to say is that you should take those side-by-side comparisons with a grain of salt.

[srce]

Timely thread, as I'm just looking at these too. Here's a table of the main spec points I was interested in:

Vendor	Keysight	R&S	Lecroy	Tek	Lecroy
Model	MSOS104A	RTO2014	HDO6104A-MS	MSO56	WavePro 254HS-MS
List price (GBP)	£21,000.00	£19,000.00	£22,500.00	£21,618.00
CPU	i5-3550S Quad  3GHz	i5	i7-2710QE Quad 2.1/3GHz	i5-4400E dual 2.7Ghz	i5-6500 Quad 3.2GHz
RAM (GB)	8	16	16	Not specified

16
 OSWindows 10 EnterpriseWindows 7 Embedded StandardWindows 7 Pro 64-bit EmbeddedClosed Linux / Windows 10 cost optionWindows 10
 HD240GB SSD200GB SSD80GB /460GB SSD
 Screen15"12.1"12.1"15.6"15.6"
 Res1024x7681280x8001280x8001920x10801920x1080
 External monitorYesYesYesYes4096x2304
 InterfacesUSB 3, 1G EthernetUSB 3, 1G EthernetUSB 2, 1G EthernetUSB 3, 1G EthernetUSB 3, 1G Ethernet
 Dimensions330H 430W 230D249H 427W 204D291H 400W 131D309H 454W 204D345H 445W 196D
 Analog Channels4440-64
 Digital channels1616160-2416
 BW (MHz) 50OHm at 1mV/div10001000100010002500
 BW (MHz) 1MOhm5005005001000
 Digital BW (MHz)400400250500
 Max BW Upgrade (MHz)80006000100020008000
 Noise @ 1mV/div 1GHZ B/W into 50Ohm (uVrms)90100145255155
 Noise @ 100mV/div 1GHZ B/W into 50Ohm (uVrms)96016505001610889
 Noise @ 1mV/div 500MHz 1MOhm (uVrms)~268130Not specified189
 Noise @ 100mV/div 500MHz 1MOhm (uVrms)~6502300Not specified1160
 Noise @ 1mV/div 20MHz 1MOhm (uVrms)~120~29Not specified64.8
 Vertical divs81010?
 GSa/s20/10102.56.2520
 Standard memory (MPts) for 4 channels active100505062.5100
 Max memory (MPts)40010002501251000
 Waveforms per second20001000000500000
 Max res  (at what b/w?)1216151615
 ADC Res108121212
 ENOB (what BW? What mV/div?)7.878.47.67.8
 SFDR 0dBm at 1GHz (dB)7268
 Phase noise at 10kHz (dBc/Hz)-121
 Min horizontal timebase (ps/div)5252020020
 Input Coupling1MOhm, AC, DC - 50Ohm DC1MOhm, AC, DC - 50Ohm DC1MOhm, AC, DC - 50Ohm DC1MOhm, AC, DC - 50Ohm DC1MOhm, AC, DC - 50Ohm DC
 BW Limiters20MHz, 200MHz, User-defined DSP - 500MHz20MHz, 200MHz, User defined20MHz, 200MHz20MHz, 250MHz20MHz, 200MHz, 500MHz, 1GHz
 FFTStandardStandardStandardStandard
 Intrinsic Jitter(fs rms)10028045060
 Jitter analysisTIE requires EZJIT option - £1600TIE requires RTO-k12 optionTIE StandardTIE standardWPHD-JITKIT option
 Matlab / User filtersOption - £1900DFP2 option
 Compliance testsBroadR-Reach, DDR, eMMC, Ethernet, HDMI 1.4, MHL 2.0, MIPI, MOST, PCI Express Gen4, UHS, USB 2.0, HSIC, XAUIUSB, Ethernet, PCIeAutomotive Ethernet
 Decode8B/10B, ARINC, DVI, HDMI, I²C/SPI, JTAG, MIPI, SPMI, PCI Express, RS-232/UART, SATA/SAS, SVID, Ethernet, USB 2.0 3.1 , USB-PD , UFS, eSPI, CAN, LIN, FlexRay, I2S, I3C - All bundled for free for nowLIN, CAN, FlexRay, I2S, MIL-STD-1553, ARINC 429, CAN FD, SENT, MIPI RFFE, MIPI D-PHY, MIPI-M-PHY, Manchester, NRZ, 8b10b, MDIO, USB, Spacewire, PCIe, CXPII2C, SPI (SPI, SSPI, SIOP), UART-RS232, CAN1.1, CAN2.0, CAN FD, LIN, FlexRay, MIL-STD-1553, AudioBus (I2S, LJ, RJ, TDM), USB1.x/2.0I2C, SPI, RS-232, CAN, LIN, FlexRay, USB 2.0, Ethernet, I2S, LJ, RJ, TDM, MIL-STD-1553, ARINC 429
 Passive Probes1 per channel - 500MHz - 9.5pF1 per channel - 500MHz - 9.5pF1 per channel - 500MHz - 10pF1 per channel - 1GHz. 10:1 and 2:1 - 4pF
 Diff probeN2750A - 1.5GHz - 2:1 - 0.7pF - 15V- 200kOhm - £2000RT-ZD10 - 1GHz - 10:1 - 0.6pF - 8V - 1MOhmZD1000 - 1GHz - 1pFTDP1500 1.5GHz - 1:1 10:1 - 0.85V  8V - 1pF - 200kOhm - £3700
 Power probeN7020A - 2GHz - 24V - 1:1 - 50KOhm - £2000RT-ZPR20 - 2GHz - 1:1 - 60V - 50kOhmRP4030 - 4GHz - 30V -  1.2:1 -0.1uFTPP0502 - 2:1 - 12pF - 500MHz
 ARBNoOption RTO-B6 - 100MHzNoOption - 50MHz- £1000
 NotesH/W buttons for all channelsDigital connector at the back No peak detect?BW limit at <4mV/div 50Ohm


Notes: List price for MSO56 includes digital probes to make it equivalent. 10GSa/s rate for HD6104A is interpolated, actual rate appears to be 2.5. Other options are available, I've just listed the ones I'm interested in. Keysight cliam measured ENOB for LeCroy is < 8. E&OE. Corrections welcome 

Probably between the Tek and Agilent for me at the moment. Tek looks pretty good apart from the noise figures and the eye watering cost of some of the extras. The passive probes sound good. The Agilent seems to have better performance and more extensive s/w options. I'd be interested to hear more from people who say it isn't necessarily the best as a general purpose scope and why?

If anyone has an MSOS104A, I'd like to know what the noise floor is when the BW is limited to 20MHz at 1mV/div.

[nctnico]

I find the waveforms/s number on the Keysight pretty low. This probably gets worse with more stuff like math enabled. The 6 channels on the Tektronix look very appealing to me.

[Marchello]

Hi!

I have on my work HDO6104 (not A) and sometime i use it with external monitor with rezolution 2560x1080 without any problems.

p.s. error in your table - HDO6104A have a 10GSa/s (not 2.5GSa/s as HDO6104)

BR
Mark

[srce]

p.s. error in your table - HDO6104A have a 10GSa/s (not 2.5GSa/s as HDO6104)

I don't think so. 10GSa/s is 4x interpolated 2.5GSa/s. From the manual:

"On "A" models, if you choose a rate greater than 2.5 GS/s, the system will automatically enter Enhanced Sample Rate, applying Sinx/x Interpolation to prevent aliasing at the higher sample rate. An upsample factor of 2 pts. is used for 5 GS/s timebases, or 4 pts. for 10 GS/s and higher timebases"

[Eric_S]

Yap, the LeCroy is 2.5GS/s, as is the Tek if you want the ADC to be 12bits, at 6.25GS/s it's 8 irrc.

If that matters to you is another story, again.


Also, if you've narrowed it down to Tek or Keysight. Perhaps you could invite them over for a demo? There aren't all that many scopes sold in the price bracket that you're shopping in, so I'd guess that they're going to be very accommodating towards you.

It's probably best to base that choice on the usage patterns that you have, rather than money that'll fade in the big picture of things anyway. So again, invite some sales people over, ask to loan it for a while and try to solve real world problems with them.

[Keysight DanielBogdanoff]

If anyone has an MSOS104A, I'd like to know what the noise floor is when the BW is limited to 20MHz at 1mV/div.

I'll grab one and check it. If you're going down to 1mV/div, I'd strongly encourage you to consider the 50ohm path instead of the 1Mohm. The 50ohm path is generally the lowest noise.

If you'd like a demo, it's often possible to work one out. You can PM me or call your local Keysight call center to get it rolling.

Also, it the ADC bits are a big thing for you make sure to ask about ENOB.

[srce]

If anyone has an MSOS104A, I'd like to know what the noise floor is when the BW is limited to 20MHz at 1mV/div.

I'll grab one and check it.

Thanks. 20mV/div would be interesting too.

If you're going down to 1mV/div, I'd strongly encourage you to consider the 50ohm path instead of the 1Mohm. The 50ohm path is generally the lowest noise.

Yes, that's true, but on the Tek spec sheet, they have it as lower for 1MOhm (64.8uV) input than 50Ohm (70uV). I guess probe attenuation comes in to it too, but it seems the Tek passive probes also support 2:1, which would be the same as some of the Agilent active probes.

Also, it the ADC bits are a big thing for you make sure to ask about ENOB.

Yep. That can be calculated from the noise figure though right?

Tek give their ENOB at 20MHz as 8.9 in to 50Ohm at 90% full screen, but don't state the Vertical resolution used. They do give RMS noise figures though at different vertical resolutions, so I think we can guess what it is. For 20MHz in to 50Ohm at 1mV/div, it's 70uVrms. At 20mV/div it's 102uVrms.

ENOB=log2(FS/(RMS*sqrt(12))

So:

log2((0.2*.9)/(0.000102*sqrt(12)))=8.9 (which suggests their vertical res was 20mV/div)
log2((0.01*.9)/(0.000070*sqrt(12)))=5.2

Keysight only specify ENOB=7.8 in their datasheet, but this is at 1GHz (and is slightly better than Tek, which is 7.6 at that b/w). At lower b/ws, the best I can see is on this Keysight blog, there is this graph:



Which suggests in "13-bit mode" it would be log2(0.1*0.9/(0.000076*sqrt(12)))~=8.4

It's not clear what b/w that is though. Possibly 300MHz from the associated text, so could be better at 20MHz. Also, I though high-res mode was 12-bits?

Although if your ENOB is <9, the extra bits perhaps don't matter, which is what I guess you are getting at 

[Keysight DanielBogdanoff]

Also, I though high-res mode was 12-bits?

I'm pretty sure that's at 12, not 13, and is just a weird/poor Excel axis label.

[Keysight DanielBogdanoff]

Melissa (you may have seen her on our YouTube channel) was able to take some measurements today on the S-Series and had a couple comments to add:

"
These are obviously not warranty specs or something we’d guarantee, but they are real measurements that you can try on your own.  Attached are screenshots, and below is my setup and results.   

My setup:
Nothing connected to channel one. 
BW limited channel one to 20MHz.
Added two Vrms measurements for AC and DC plus a Vpp.
(all of this is displayed in the screenshots as well)

Results:
20MHz BW, 1mV/div, 1MOhm input
Mean baseline DCVrms noise = 156 uV

20MHz BW, 1mV/div, 50Ohm input
Mean baseline Vrms noise = 180 uV

20MHz BW, 20mV/div, 1MOhm input
Mean baseline Vrms noise = 366 uV

20MHz BW, 20mV/div, 50Ohm input
Mean baseline Vrms noise = 288 uV


This is a quick measurement that anyone can verify on the spot to check noise, which they might enjoy.  But I would also strongly direct people more towards system ENOB to determine the signal integrity of their oscilloscope.  One thing to pay attention to is that we specify system ENOB for the S-Series in the datasheet. Some others only include ADC ENOB, which does not come close to telling the whole story because that only specs one single component within the system and disregards the effects of the front end, clocking, and the rest of the oscilloscope design.

For some more resources, here's an App note on SI:
http://literature.cdn.keysight.com/litweb/pdf/5991-4088EN.pdf

And a blog on SI:
https://community.keysight.com/community/keysight-blogs/oscilloscopes/blog/2016/09/01/how-does-oscilloscope-signal-integrity-impact-your-measurements-and-analysis
"

I hope this helps!

[srce]

Also, I though high-res mode was 12-bits?

I'm pretty sure that's at 12, not 13, and is just a weird/poor Excel axis label.

It's 13 elsewhere in the blog too. E.g. in this table:

Bandwidth	RTO2000 High Def Mode	S-Series High Res Mode
10 kHz – 50 MHz	16 bit	13 bit
100 MHz	14 bit	13 bit
200 MHz	13 bit	13 bit
300 MHz	12 bit	13 bit
500 MHz	12 bit	12 bit
1 GHz	10 bit	11 bit

Unfortunately in the demo of the Infiniium s/w, you can't open the Acquisition dialog to see what choices there are and it doesn't say in the help. But, I guess it doesn't actually matter, given you're not getting close to that number of bits anyway.

[srce]

Results:
20MHz BW, 1mV/div, 1MOhm input
Mean baseline DCVrms noise = 156 uV

20MHz BW, 1mV/div, 50Ohm input
Mean baseline Vrms noise = 180 uV

20MHz BW, 20mV/div, 1MOhm input
Mean baseline Vrms noise = 366 uV

20MHz BW, 20mV/div, 50Ohm input
Mean baseline Vrms noise = 288 uV

Thanks to you both. I think it's the AC RMS values from the screenshots that you want to promote though

Scope	BW	Vertical setting	Input	Noise AC RMS	ENOB limit based on noise
MSO56	20MHz	1mV/div	50 Ohm	70uVrms	5.2
MSO56	20MHz	1mV/div	1 MOhm	64.8uVrms	5.3
MSO56	20MHz	20mV/div	50 Ohm	102uVrms	9
MSO56	20MHz	20mV/div	1 MOhm	104uVrms	8.9
MSOS804A	20MHz	1mV/div	50 Ohm	48uVrms	5.4
MSOS804A	20MHz	1mV/div	1 MOhm	115uVrms	4.1
MSOS804A	20MHz	20mV/div	50 Ohm	260uVrms*	7.3
MSOS804A	20MHz	20mV/div	1 MOhm	139uVrms	8.2
RTO2014	20MHz	1mV/div	50 Ohm	33uVrms	6.3
RTO2014	20MHz	1mV/div	1 MOhm	29uVrms	6.4

* This looks a bit fishy to me, as it's far higher than the speced noise for the MSOS104A at 1GHz. (Which is 163uVrms). It does appear to be the MSOS804A the measurement was made on, from the 8.40 GHz at the top of the screen. But if the b/w is set to 20MHz, that shouldn't matter should it? Does one of the other b/w limiters need to be on too? For the 1MOhm screenshot, the 8.4GHz drops to 500MHz.

[Neganur]

There’s global bandwidth limit and per channel setting.
I can do those for you on a 1GHz model (does the time/div matter?)

[srce]

There’s global bandwidth limit and per channel setting.
I can do those for you on a 1GHz model (does the time/div matter?)

Thanks  - It could do, if you had it really as a really tiny interval. 1us as in the above pics seems OK.

I did notice you had the DSOS for sale. How did you find it overall?

[Neganur]

Noise AC RMS V/div 50 1M ------- | -------- | --------- 1mV | 42.7 uV | 135 uV 20mV | 119 uV | 151 uV Out of curiosity, since noise seems to change with sampling rate and memory depth, I fixed the amount of memory and swept the sampling rates. The data is summarised here: 50Ohm, 1 mV/div, 20 MHz BW limit | 100ns/div | 50us/div GSa/s | 20 kpts 1 Mpts | 10 Mpts ------- --------- --------- --------- 20 | 42.6 uV 42.7 uV | 44.1 uV 10 | 43.4 uV 43.8 uV | 44.9 uV 5 | 52.6 uV 52.7 uV | 55.9 uV 2.5 | 51.7 uV 51.7 uV | 54.9 uV 2 | 53.8 uV 54.0 uV | 57.3 uV 1.25 | 51.9 uV 51.9 uV | 55.3 uV 1 | 53.7 uV 53.8 uV | 57.2 uV 0.5 | 50.6 uV 50.5 uV | 53.8 uV 50Ohm, 20 mV/div, 20 MHz BW limit | 100ns/div | 50us/div GSa/s | 20 kpts 1 Mpts | 10 Mpts ------- --------- --------- --------- 20 | 135 uV 135 uV | 132 uV 10 | 151 uV 150 uV | 151 uV 5 | 331 uV 330 uV | 360 uV 2.5 | 337 uV 339 uV | 370 uV 2 | 301 uV 300 uV | 328 uV 1.25 | 364 uV 363 uV | 395 uV 1 | 310 uV 311 uV | 340 uV 0.5 | 319 uV 318 uV | 350 uV (Those odd jumps at 1.25 GSa/s are not measurement errors. I repeated those and got the same every time)

[Rich@RohdeScopesUSA]

Hi srce - a couple tweaks for the RTO2000 portion of your table (looks like you might have had an old datasheet - here is the latest version:

https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/RTO2000_dat-sw_en_3607-2684-22_v1601.pdf

1.  We run a Core i5 with up to 16GB of RAM.  The majority of our analysis work is done in a custom ASIC so we don't rely on the CPU as much.
2.  We have USB 3.0 ports
3.  In addition to the standard analog filters (20MHz and 200MHz), we also offer digital filters that are handled in our custom ASIC with a wide number of user-definable choices.
4.  In addition to USB 2.0, PCIe 1.1/2.0 and Ethernet (10G, 100Base-T1, 2.5/5G, EEE, 1000Base-T1) compliance, we also offer MIPI D-PHY and eMMC.
5.  We offer a very broad amount of trigger/decodes (not just decodes like some other scopes):
I2C/SPI Serial Decoding
UART/RS-232/RS-422/RS-485 Serial Decoding
CAN/LIN Serial Triggering and Decoding
FlexRay™ Serial Triggering and Decoding
I²S Serial Triggering and Decoding
MIL-STD-1553 Serial Triggering and Decoding
ARINC 429 Serial Triggering and Decoding
Ethernet Serial Decoding
CAN-FD Serial Triggering and Decoding
SENT Serial Triggering and Decoding
MIPI RFFE Serial Triggering and Decoding
MIPI D-PHY Serial Triggering and Decoding
MIPI M-PHY Serial Triggering and Decoding
Manchester and NRZ Serial Triggering and Decoding
8b10b Serial Decoding
MDIO Serial Triggering and Decoding
IEEE 100BASE-T1 Serial Triggering and Decoding
USB 1.0/1.1/2.0/HSIC Serial Triggering and Decoding
USB 3.1 Gen 1 Serial Triggering and Decoding
USB Power Delivery Serial Triggering and Decoding
USB 3.1 SSIC Serial Triggering and Decoding
SpaceWire Serial Triggering and Decoding
PCI Express 1.1/2.0 Serial Triggering and Decoding
CXPI Serial Triggering and Decoding
6.  For the diff probe, you'll want our RT-ZD-series, not the RT-ZS-series.

Sounds like you are leaning towards Tek or Keysight already (both good scopes), but if you'd like to try out a RTO2000 our team in the UK can get you one easily - just PM me.

-Rich

[Rich@RohdeScopesUSA]

(Those odd jumps at 1.25 GSa/s are not measurement errors. I repeated those and got the same every time)

In general, there are two components that dominate noise - the front end and the ADC.  The front end dominates at smaller volt/div settings and the ADC dominates at larger volt/div settings. 

I'm guessing the reason you are seeing a large jump in noise when you go from 10GS/s (and above) to 5GS/s (and below) is I believe the S-Series is only 10-bits at 10GS/s and above.  Below that it runs at 8-bits.  This would explain why you see the biggest jump in your second table (the larger volt/div setting).

Perhaps Daniel can clarify or explain if I have misunderstood how the S-Series operates.

-Rich