Hi,
Having a similar issue here. Halion 6, Cubase 9.5, Macbook Pro 2014 i7 16Gb ram 512Gb Ssd drive.
Have Cubase 10 on my PC but not yet installed on the Mac.
I have had Halion for a while but have barely used it. Now came the time as I started doing a more synth oriented music. To my surprise on a very simple project I noticed my Real Time Processing in the Perf. Meter getting very high. I had three slots loaded on Halion, reduced it to one, still problematic.
Increased buffer but it became impractical above 512 for playing live, too much latency. Started feeling bummed. Some great sounds in Halion. Does not seem to be greatly appreciated in USA but it is a beast and some compare it to UVI Falcon.
Decided to do some testing today. Empty project, one instrument track with Halion, one midi track to trigger from midi input, I prefer doing it like that, loaded one slot, play sound from EWI. Super high RTProcessing. Went to Cubase and de- selected multi core processing by VST Asio settings and selected multicore on Halion, that helped a little. Reduced number of voices to 16, still too high and showing red spikes on Halion’s CPU meter.
Finally decided to run Halion in stand alone mode and that made a huge difference. Since I was interested in using it with an EWI, I edited the loaded sounds to receive CC2 for note on and then selected voice management “on” and then “mono”. With three sampled based wind instruments the CPU was hardly moving on Halion, tons of performance headroom. Tomorrow I will test with more CPU intensive instruments.
So it looks like Halion has to be set up right to work as VST in Cubase and I am hoping that eventually the tweeks will make it usable so I can record itscwondeful sounds.