I have never had a hub between the Octocapture and the computer.  It as always been directly connected.  Maybe "currently" was a poor choice of wording.

I think you should select "low latency mode" in your octacapture driver settings. It is probably grayed out because the interface is in use (by Sonar?). I did see in the manual, that this setting does nothing if you are using the VS Expand option, so that might also be the reason that this is grayed out. I would suggest you try swithing VS Expand off, then swith Low latency mode on (if possible), then check the latency again... All when making sure Sonar is not runnning (except of course when testing latency again :).
 

HighestOlive
I have never had a hub between the Octocapture and the computer.  It as always been directly connected.  Maybe "currently" was a poor choice of wording.

That's good.

I think the VS expand setting is used in connection with the VS series of Roland Audio Devices so yes this should be set off.

mudgel
I think the VS expand setting is used in connection with the VS series of Roland Audio Devices so yes this should be set off.

Yes, but I also believe that this setting is needed if you use more than one octacapture as well. And he mentioned in his first (or so) post that he sometimes uses 2 octacaptures... So it might be needed sometimes, but not all the time :)

That is correct.  I have two octo-capture,so that should be on.  Some time I don't turn both on.  It depends on how many inputs i need.

c5_convertible
I think you should select "low latency mode" in your octacapture driver settings. It is probably grayed out because the interface is in use (by Sonar?). I did see in the manual, that this setting does nothing if you are using the VS Expand option, so that might also be the reason that this is grayed out. I would suggest you try swithing VS Expand off, then swith Low latency mode on (if possible), then check the latency again... All when making sure Sonar is not runnning (except of course when testing latency again :).
 

I will try this.  I think I made a mistake earlier when flipping this on an off while sonar was running.  You are right that sonar probably needs to be off when doing this.
 

HighestOlive
Looks like real latency.

 
Sort of. SONAR's showing 73 samples more round-trip latency, which is considerable, and the driver usually under-reports. Typically, the measured value will be 20-40 samples greater than reported by the driver to SONAR.
 

Having just sonar open (no project) I see this roundtrip latency reported in the driver setting.  If I open a proejct it goes to the value seen above.

 
I don't understand this. You're saying CEntrance reports 850 samples when SONAR is open with no project (i.e. audio engine not engaged), and 777 when a project is open? That's a little weird; it's very close to what you'd expect for the difference between 44.1kHz and 48kHz. In any case, I suggest you check again with SONAR shut down.
 
Like others, my first thought was that something is going on with your USB port drivers, but I don't think SONAR detects latency added by USB. It seems to me whatever is going on is all happening in the Octacapture hardware/firmware/drivers. Some re-installation might be in order, but if CEntrance is measuring such a high latency at a buffer of 128 samples, I would take that to Roland support as it's not a SONAR-specific issue.
 
 
 
 

Is it just me?  I don't see 17ms RTL with 128 sample buffer to be that bad.  I'm happy as can be with 8ms RTL @ 64 samples.
 
 

It's easy to see if reported is correct or not.
 
Just make a analog loopback on interface - and record metronome on that track.
If they line up reported is correct.
 
Then that is estabilished you can go on and see what really makes it that high.
I would surely turn off that expand thingy and see what happends.
 
Are the any usb dongles - iLok or Syncrosoft?
Remove those while doing tests and see if different with and without.

lfm
Just make a analog loopback on interface - and record metronome on that track.
If they line up reported is correct.

CEntrance does the measurement for you, and is sample-accurate without exception in my experience.