I only just got my Octa last week but first thing I did was ticked the  reduce CPU Load button.

Maybe you had it ticked before and changed it without meaning to ?

It is un ticked as default. Might be worth a try :)

Hi,
Don´t know if it has been suggested  before, but 
is it still possible for you to try the windows system recovery to a date 
short before the problems?
best luck
Pragi

You can't change the sample rate on the Octa from within Sonar, that's why you are getting the error message. AKAIK, the only way to change the rate is from the front panel. Press/hold the DISPLAY button on the Octa and sample frequency will be the second line option. Navigate to it with the knob above display button and change it to 96hz or whatever you choose. Then you have to power cycle the Octa for the change to take effect. As mudgel said, the higher rate will improve your roundtrip latency. On my system it is about 9 or 10 msec at 44Hz/64 samples. I get it down to 8.1 at 96Hz/128 samples (it actually goes up to 8.4msec at 96 samples). I actually think 9msec is very functional though understand your frustration if you have achieved better in the past.

I wonder if you accidentally changed the rate on the Octa while fooling with the multi-function knob or reset the driver settings on the Octa ontrol panel? I think 44.1 is the default setting which is prob why plugging in the new unit didn't help.

I wouldn't disable the onboard sound in the BIOS. That can cause problems. Just don't select it in Sonar. 

Have you tried WDM mode just to see what happened? Do that and run the Wave Profiler to see what settings it comes up with. 

Do you have the Octa Capture connected to a USB port on the computer and not a hub?  

You did download the latest driver from Roland, right? Should be version 1.5.1.

Did you change anything on the computer, like add memory, overclock the CPU, or tweak any system settings before the problem started? What is your Windows Experience Index (Computer-Properties)?

Do you have the Octa Capture set to the same sample rate and audio buffer size as you have set in Sonar? 

Do you have ASIO Direct Monitor checked? 

Do you have all of the updates for Windows 7 installed (I believe its at SP1).