Cubase Performance/Dropouts/Audio Load Spikes, etc

So I built a super pc some years ago and it never performed great with Cubase 10.5 (still on 10.5). This computer should have taken whatever I could throw at it. I sort of put it on the back burner and just dealt with it but im fed up and need help. In the link below you can see a video of a heavy project not playing back audio at all, with the audio perf load freaking out, despite not exceeding 20-30 percent of the CPU and with latency monitor not showing any red flags. Granted I do have a ton of cpu intensive instances of plugins like Equillibrium and Soothe 2 etc.

I know this pc is considered old now but I never got good performance. What am I missing?

BTW Lynx hilo Thunderbolt for interface and buffer maxed to 8k! Insane. Please halppp

[Cubase Sucks.mp4 - Google Drive]

I build a top level PC a few years back and had some poor performance with Cubase at times - not sure what version… 10.5 sounds about right. I’m on 14.0.10 now and the machine does great.

upgrading NOW lol, sold

Let me know how you do.