TIP: you can check your Mac's drive type at the 'System Information' report (click  > About this Mac > System Report. Contact your local Apple Authorised Service Provider to get assistance with the disk replacement. This is the #1 recommendation for all Mac users which gives the significant performance boost to Mac at 2-3 times.

If your Mac uses a hard disk drive (HDD), it is highly recommended to replace the drive with a solid-state one (SSD). Upgrading Your Mac with a Solid State Drive While CPU cannot be replaced at hand, most of Mac computers enabled for RAM and hard disk upgrade. The computer's performance mostly depends on several hardware components: CPU, RAM, and hard disk. Clicking on a process name will open Windows Task Manager showing selected process: Click on CPU Usage monitor to see what processes in Windows use the computer's CPU. Look at the VM window tray and CPU Usage Monitor will light up in red when CPU usage in Windows is above 70%. Note: starting with version 14, Parallels Desktop for Mac brings a new feature: CPU Usage Monitor. It is also very important to allocate even shares of hardware resources between the host operating system (macOS) and guest (VM) according to the recommended system requirements of both systems. Virtual machine performance is directly related to a computer's hardware resources. Multiple anti-virus programs have been installed.Too many resources have been assigned to the virtual machine.Using an outdated Parallels Desktop version or build.There might be multiple reasons causing the low performance, such as: I am not satisfied with Parallels VM performance.I am not satisfied with my Mac performance when I run Parallels Desktop virtual machine (VM).

Ways to optimize mac performance