You may want to peruse the parallels support forums, if you are just doing normal stuff like that something is not right- mine is very fast and others have said the same. I would focus on some of the parameters, something mau be set wrong. Here is one good one that highlights some of the most obvious settings- it's from a knowledge base article dated July 2019:
Virtual Machine Configuration
- Shutdown your VM > open its configuration > switch to Hardware tab > CPU & Memory > make sure that the number of processors (CPUs) selected is not maximum (e.g. 4 out of 4). In most cases, half of total CPUs will provide optimal performance. Assigning more than a half of CPUs for the virtual machine may cause performance degradation for both Mac and VM.
- Make sure that memory allocation is within the recommended level. Similarly to processors, best practice is to assign half of Mac's total RAM.
NOTE: The amount of memory assigned to a virtual machine must be multiple of 1024 or Windows may behave inappropriately. E.g 1024, 2048, 3072 MBs and so on.- Under Advanced settings make sure that 'Parallels' hypervisor is selected.
- Under Hardware > Graphics set Memory option to Auto (Recommended).
NOTE: For Windows 10 virtual machines make sure that under Advanced Settings 3D acceleration is set to DirectX 10.- If your Mac uses an HDD or a FusionDrive (not SSD), make sure that the option TRIM is disabled: go to Hardware > Hard Disk 1 > Advanced Settings > uncheck Enable TRIM option.
- Start you virtual machine and test performance.
These are amazing tips
