Rhino 8 Slow performance in rendering

Hello, I wanted to report Rhino 8 “Material thumbnail loading” problem. they are black and they won’t load.
and Slow Viewport performance right after I Add A material.
There is also a difference in color and sharpness between Rhino 7 and 8 Raytraced viewport with exactly the same settings.
I also faced render mesh generation problems when I Used drape and other commands in Rhino 8. It either fails or gets too slow to generate them. having no such problem in Rhino 7. Is it because of the freshness of Rhino 8 or is it a problem on my side that I can fix?

Please start with posting the unabridged results from the Rhino command _SystemInfo.

Rhino 8 SR1 2023-11-21 (Rhino 8, 8.1.23325.13001, Git hash:master @ 8a4a437248efac5d9cb04d3904481b83e4c23a64)
License type: Commercial, build 2023-11-21
License details: Cloud Zoo

Windows 10 (10.0.19045 SR0.0) or greater (Physical RAM: 32Gb)
.NET 7.0.0

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 2070 (NVidia) Memory: 8GB, Driver date: 6-8-2023 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 536.23
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port #0

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 3-17-2022
Driver Version: 30.0.15.1215
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

Rhino plugins that do not ship with Rhino
C:\Program Files\Chaos Group\V-Ray\V-Ray for Rhinoceros\V7\VRayForRhino.rhp “V-Ray for Rhino”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\RhinoCode\RhinoCodePlugin.rhp “RhinoCodePlugin” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.1.23325.13001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp “Displacement”

There have been a host of fixes since Rhino 8.1. Please set your update frequency to service release candidate and update to Rhino 8.4

Also, update your Nvidia drivers, doing a clean install: when the driver installer is started selected custom install and from that check clean install. Your drivers are recent, but they need to be even more recent for better stability.