Massive VST overloads with UAD Apollo USB

Just installed a new Apollo USB and been testing the new setup.

Running a very basic 24/48 project with only 3 instances of Kontakt 5 and with the buffer set to anything less than 2048 the realtime meter is maxing out constantly, leading to horrendous crackling. Asio-guard alleviates this somewhat and lets me drop the buffer down to 64, but the realtime meter is still running over 50%. With a big project loaded it’s completely unusable no matter what my settings are.

Did an identical test on PT12 and have none of these issues, tried cranking it to 50 simultaneous Kontakt instances and it still barely registers on the CPU.

Happens in 8.5 and 9. I used to have a UR-44 but had to ditch it because of compatibility issues that have never been addressed (spotting the Steinberg theme here?!), however I could still run huge 24/96 projects with a 64 buffer and never ran into issues like this.

I realise this is a UAD/Cubase compatibility issue so have also posted this on their forums, but if anyone has got any ideas I’d be very grateful because this is creating real problems at the moment!

Just shows how flakey things are in the Cubase world! I went from a UR44 (which I thought was excellent) to an Apollo quad + satelite quad, no issues so far in 8.5 or 9. Performance is excellent. Ensure you’re monitoring through the Apollo, turn Cubase direct monitoring off.

Hmmm, maybe you have better performance because you’re running FW and I’m using USB? What buffer size do you have set?

I checked direct monitoring but it was greyed out so I presume it’s not supported by the Apollo.

Sorry, read but didn’t digest the USB bit - My buffer size is usually set to 1024, as monitoring is direct the latency isn’t an issue. Although I have tried 128 and that was fine too.

I have a FW Apollo and in the console there are some bandwidth tuning settings that made a big difference for me. Does the USB Apollo have something like that? There may be something restricting your bandwidth.

Other things to consider, if you are using Cubase’ s ASIO Guard turn it off. That usually does more harm than good with UAD Units.

Another thing that can cause this is disk traffic/overloads. Are your Kontact libraries on a separate drive?

I had a poke around the console and couldn’t find anything relating to bandwidth, maybe that’s a FW thing?

Strangely enough, despite never needing to use ASIO guard with the UR44 I have to have it turned on max for the Apollo otherwise it’s completely unusable.

I’m running the all libraries off a separate SSD so I can’t imagine any disk overload issues there.

Just a small update, I’m now running it stably at 512 with ASIO guard on max and it seems to be coping alright. Very disappointed that I can’t set the buffer down to 64 though! I also get occasional freezes where the system will lock for a second before coming back, and when it does the CPU meter has a registered peak.

Does anyone know of a program that can run in the background and see what process is causing these random glitches?