Rigol DS1074Z sample rate and mem depth limit

[eyal]

I had this DSO for a few months and I notice that under all conditions I never see a "Sa Rate" above 500MSa/s or a "Mem Depth" over 6M. It is supposed to do 1GSa/s and a depth of 12M (without options).
This is with one channel enabled and no averaging etc.

I now installed the latest fw and this did not change.
    Model:DS1074Z
    Board Ver:0.1.1
    Firmware Ver:0.2.3.11
    BOOT Ver:0.0.1.2
    CPLD Ver:2.3
    SoftWare Ver:00.04.03.SP2

Interestingly, this is the case with a single channel 1, 3 and 4. However ch2 does not have this limitation. What gives?

I searched this forum and scanned the bugs/wishes but did not see this mentioned (but maybe I missed it).

TIA

[Orange]

When you select CH1, you also need to set the trigger source to CH1, if you leave that on CH2, it does only 500Ms/s

[Fungus]

Both values are affected by the memory depth option under the 'acquire' menu (press the "Acquire" button).

The sample rate goes down at lower memory depths.

Have a fiddle with that setting.

[eyal]

Thanks @Orange, you are correct. Selecting AC as the trigger source allows all channels to sample at 1GSa/s with a depth of 12M. I can see how it needs to use a comparator (or the ADC) but I did not expect the trigger to need half the memory. I guess the design is hardwired to store each sample even when it is not required (or is there a way to display the trigger trace, AC in this case?).