The Mac OS equivalent of DxDiag on Windows computers is the System Profile.
The System Profile is a diagnostic tool that shows all the technical information about your computer (graphics card model, amount of memory on the hard drive, operating system version).
No confidential information is collected.
How to get a system profile:
To see basic information about your Mac, choose Apple menu > About This Mac.
You can also find this information in General settings, where you can see more details including warranty and repair coverage and generate a detailed system report.
On your Mac, choose Apple menu > System Settings, then click General in the sidebar. (You may need to scroll down.)
Click About on the right, then click System Report.
You can also press and hold the Option key, then choose Apple menu > System Information to open the system report.
Save a system report: Choose File > Save, then enter a name and choose a location for the report.
in the sidebar. (You may need to scroll down.)