Noise values for one "Industry-leading system architecture: 18-bit vertical resolution/12-bit ADC" are not so exceptional low as R&S would like them to be.
For MXO4 is stated - RMS noise floor ( HD mode
active for bandwidth ≤ 500 MHz)
sensitivity:
HDO4: analog bandwidth 1 GHz LeCroy HDO 1 GHz
0.5 mV/ 98 µV
1 mV/ 104 µV 145 μVrms
2 mV/ 116 µV 145 μVrms
5 mV/ 152 µV 150 μVrms
10 mV/ 238 µV 155 μVrms
20 mV/ 436 µV 185 μVrms
50 mV/ 1.01 mV 275 μVrms
100 mV/ 2.47 mV 500 μVrms
200 mV/ 4.43 mV 1.75 mVrms
500 mV/ 10.13 mV 2.75 mVrms
1 V/div 19.96 mV 4.90 mVrms
For example, every LeCroy HD Oscilloscope has in sensitivity over 2mV significantly better values, partly 4x better!
That is not bashing, only pure facts.
This is why we post our noise figures - so people can decide what is most important to them. In our research talking to customers, the smaller volt/div settings were the most painful for them when noisy (e.g. see the Marco Reps video above). If you think of it as a percent of scale, versus just an absolute number (I believe LeCroy uses eight vertical divisions versus ten for us), you can see noise is much more impactful at the smaller volt/div settings. This is also true as you move up in bandwidth - the signals are typically smaller with less margin for error, so having better noise performance on the smaller settings becomes more important.
R&S LeCroy
Scale RMS Noise % of Full Scale RMS Noise % of Full Scale
0.001 0.000104 1.0% 0.000145 1.8%
0.002 0.000116 0.6% 0.000145 0.9%
0.005 0.000152 0.3% 0.00015 0.4%
0.01 0.000238 0.2% 0.000155 0.2%
0.02 0.000436 0.2% 0.000185 0.1%
0.05 0.00101 0.2% 0.000275 0.1%
0.1 0.00247 0.2% 0.0005 0.1%
0.2 0.00443 0.2% 0.00175 0.1%
0.5 0.01013 0.2% 0.00275 0.1%
1 0.01996 0.2% 0.0049 0.1%
But again, your needs may vary. Wish we never had to make design tradeoffs, but like everyone, we do.
-Rich