Minecraft little FPS with good PC?

I have quite a few FPS in Minecraft with my relatively good PC.

Without shaders I have 100-250 (that does not bother me either)

But with Shader I have 20 to 60FPS maximum

My specs:

RX580 8GB (1450MHz)

Ryzen 5 2400G

16GB 3000MHz RAM

400 watt power supply

Java Version: 1.8.0_221 64 bit

Are the shaders maybe optimized for OpenGL?

Sure, that you also use the graphics card and not the graphics chip of the APU?

Because it is a ryzen, it is a multitask processor, if you want 100% load you buy an intel, otherwise just a stronger ryzen.

With which shaders? Some are just damn poorly programmed and therefore need a lot of power. With the Zeus shader, I even have only 60 fps and my system is slightly better than yours.

Otherwise, look at the advanced settings of the version before starting. Standard is there really little ram set. For JVM arguments, just enter "-Xmx12G" or change this value

Ok then another approach you have the problem from the beginning or falls off the FPS over time. (e.g., at the beginning of 150 and after 10 minutes, still 25).

Ne from the beginning

How much RAM does MC get (press ingame F3 and then looking right)

4GB

Where do you see that?

Yes, everything is connected to the GPU

My MC I have assigned 4GB and it will be used with shaders about 1-3 GB