Blender 2.8 running slow

) I made a character and uploaded it to mixamo.com, I have some animations I got from mixamo.com for my character in my Blender file. but the animations are running very slow. It was running a lot faster on mixamo.com and if I open it in 3D viewer it runs fast, but it is running so slow in Blender? even using eevee? how can I fix this ?

  1. I made a forest and I added some lightning and a character and again everything runs so slow and I do not know why. the Scale is X = 20, Y = 20, z = 20 and Dimensions are X = 201m Y = 202m Z = 32 m

So it is not a big forest at all:
the Blender file at the bottom right says:
Verts: 1, 621,609
Faces: 846,250
Tris: 1,625,889
Object: 0/114
Mem: 2.77 GIB

IDK if that is bad or not…

Blender’s current viewport performance isn’t that great. That being said, there are few things you can do to make it a bit faster.

Disable auto smooth in object properties if there are any that have it enabled.

Remove/disable normal map nodes in shaders.
Here’s a workaround to use instead so you don’t lose all the details: Way Faster Normal Map Node (for realtime animation playback with tangent space normals)

Disable subdivision in viewport.

Rendering wise the biggest performance hits in eevee are volumetrics, amount of lights with shadows, transparencies, SSR (especially if you are close up to a material) and heavy usage of depth of field.