What kind of graphics card is integrated into the RYZEN 7 4800H processor
What are its details, how do I test its performance, and with any other card equal to it from the separate cards?
It uses Radeon Graphics ( I believe it is an updated Vega Graphics version).
Here one review of that laptop Processor with test charts in various test programs and comparison to other Laptop Processors: https://www.techspot.com/review/2018-amd-ryzen-4800h/
"The Ryzen 9 comes with a fully unlocked Vega GPU with 8 compute units and a 1750 MHz max frequency. Meanwhile, the Ryzen 7 4800H has 7 compute units clocked at 1600 MHz. On paper there's a difference, but we don’t expect any H-series laptops to launch without a discrete GPU pairing, making the point moot."
A separate Discrete GPU card will always be more powerful than an Integrated Graphics. One of the main reasons is that the Integrated Graphics has a vRAM Memory limit of less or the same amount as 2GB generally via BIOS setting whereas Discrete GPU cards can have 4GB or higher of vRAM Memory installed.
Possibly today's latest Laptops the vRAM Memory might be more than 2GB maximum but not sure of that.
There are several ways to test your Integrated Graphics for performance. Download a testing program that test performance for laptop processors.
I was going to mention Cinebench but it seems to require a minimum of 4GB of GPU vRAM Memory to work.