Performance Loss and Central Page Usage

Hi optimum,

Thanks for reaching out to the Sophos Community Forum. 

If disabling the Realtime Scanning option has alleviated the performance issue you're experiencing, I recommend adding a Process Exclusion from the Threat Protection Policy or the Global Settings page for the main executable. 
The file/folder exclusion will prevent scanning from occurring when those specific files are accessed, whereas a Process Exclusion will white-list the operations performed by the process including files that it touches.

I also recommend checking if the process is reaching out to external directories such as shared folders to get additional information or if the process only runs locally on the device.

Hello again,
The Global Settings >> "Allowed Applications" directive didn't work.
After that;
I added the software we use with the People>>Person>>Policies>>Thread Protection>> Under Settings >>Exclusions>> "Add Exclusions" directive.

However, there are still differences when I open a design with solidworks, for example, in my control. When I close the files in the real time scanning section of the antivirus's settings page, I can reach the required speed.

Could you please explain the settings you describe as follows ( f.e: People>> Person>> Pol...... )
Or is there an opportunity in Sophos central to make exceptions for files with the following extension? For example, files with the x_t extension that we use in Solidworks software. I wonder if we can gain a little more performance in this way?

What are the consequences of closing the "files" under the real-time pictured?

I'd like to look into the types of exclusions you are adding, I have reached out to you via PM to inquire further. 
For reference, the different types of exclusions you can create are outlined in the following document.
- Global Exclusions

Disabling the Files option as shown in your screenshot will disable "on-access" scanning. This will also affect Application Control and Malicious Behavior Detection. Other features shown in your screenshot will remain active.