FWIW I have an old dual core pc running win7 with a firewire interface in WDM mode (it just works better that way than ASIO - I have no idea why) and Sparkle has always worked fine in whatever CW version I was using at the time. That said, it's been a while since I used it last so I haven't tried on the latest CW version which seems to struggle even playing back some projects that played fine in the version I had installed before (2019.09 IIRC) and also synths seem to hit the cpu more than previously too. I'm seriously considering reverting to 2019.09 as there seems to be no up side of having the latest version in my case.