Which Mac to buy for Cubase Pro 9.5


I use Cubase pro 9.5 on Mac Pro 6 cores 3,33 ghz 5.1 2010 with 32 Go RAM 1333 Hyperx Predator 480 SSD (High Sierra)

2 SSD Sandisk on PCI Sonnet Tempo Card For Samples & Libraries Kontakt

4 HD internal

RADEON 7950 Mac Edition Video Card with 3 screen Samsung Curved

The problem is when I have a large session with ten VST instruments Nexus Kontakt …

and Plugs from UAD with PCI EXPRESS DUO CARD and others

The mixer vu meter have strange reaction slowly reacting like not enough video memory

the cpu is 60 % used in the cpu Performance Cubase

so I don’t Know if I can get better GUI or video performance buy changing the video card for a Sapphire Radeon RX 580 Pulse 8 Go

and upgrade my six cores two 12 cores 3,46 ghz with more ram

or simply changing my Mac for a new But which ?

can someone help me please

thanks to All