Cuda and Optix are both Nvidia exclusive technologies and for the purpose of doing rendering in blender are generally faster than AMD cards using OpenCL technology (though this is largely to do moreso with the monopoly Nvidia has and them not playing nice with AMD rather than their cards inherently being better.) But yes, they are important. If you have a ...
Blender can use CUDA for rendering with Cycles. It's a very important feature used by a huge part of users of Blender. This technology has a great impact on rendering so it does matter to a lot of people.
If you encounter any problem toward Undo system, please help to file up that bug to the bug tracker in Blender develop. There is a new undo/redo system been adopted due to the old one was bulky in some situation.
A quick way to fix your strange behavior is to use old system instead of new one:
By checking Developer Extras in Preference-
And choose ...
If you are loading a very large project onto blender, it may be best to wait for your output.
For example, i loaded 53,000 chunks of a minecraft world into blender, waited, and got my country loaded block by block.
I know I'm late to the party, but I'll leave this here for reference. Blender Internal is an extremely outdated engine, hence why they replaced it in 2.80 with Eevee, which is far superior in every way.
The most prominent difference between Eevee and Blender Internal is that, while Blender Internal renders offline using the CPU only when you manually go to ...