I have some slow files I need to fiddle with.
Every action takes loooooong, even a simple move of an object can take 30 sec.
I thought it’s a good idea to disable Undo.
That worked in previous versions by setting the Undo steps to 0.
In V8 I can set this value, but after restarting Rhino the value is 1.
While Undo steps is set to 0, Undo still works.
Limiting the memory doesn’t have an effect as well.
How to disable Undo, at least for a running session?
No idea how to do this, but does it really speed things up?
That’s what I want to explore…
…with not very much hope.
I somehow managed to skip Undo by setting both values to 0.
You are right, every geometry operation is still slow.
Same as with Undo.
What really helps is to make blocks from the geometry parts.
To get an impression:
The display speed is fine.
The calculations seems to be ok as well, see the scaling.
I think you need an nitrogen overclocked CPU, going at a good 9.6 GHz single-threaded to resolve these kinds of Rhino issues. I also see this very regularly in the Rhino 8 Commercial (Not Responding) edition.
Seems considerably worse than Rhino 7, but I haven’t used R7 in a while.
Is this not the sort of mesh you can remesh?
Exactly what I use in here.
Not so much faster in V7, what takes a minute in V8 takes 45 sec. in V7.
Sure, but I want to point out a problem.
I think the transformation is instant. You see the yellow preview shape moving immediately. At least if its a mesh.
I guess the problem is more related to the rendering. What sort of geometry is it and how dense is the render-mesh tessellated? Are you also using textures?
If your render-mesh is even denser and your GPU is weak (or disabled ->Laptops), you can have the best CPU, it wouldn’t help you.
Other than that, Rhino was always a bit weak when it comes to lots of data, but the question is also why is it so dense in the first place.
If it’s a Surface model with high-order NURBs, also consider that it needs to calculate a lot of things if your shape consists of multiple thousands of such surfaces.
Yes, but what happens when the transformation, a simple shift in this case, gets applied?
I think the geometry database gets updated somehow.
When I blockify the offending object, then all transformations are instant.
When I set _RedrawOff, then rendering shouldn’t happen.
The transformation is not faster.
EDIT:
The same slowness is observed when I copy+paste the object.
Also with _RedrawOff.
It is a very stupid bad SubD, very dense.
Only good to show performance issues.
It is also weak with less data, there are many samples around on Discourse where simple 2D curves are slow to handle.
The more data the less speed.
There is a bottleneck somewhere.
I think it could be an idea to investigate where it happens.
Perhaps it is a simple thing, like appending something to memory by copying it over and over in old, practically never touched code.
Just a wild guess.
Hmmmm … just guessing … (No Rhino 7/8 here, I cannot check 
)
I think that transforming a block only changes its transform matrix from the original objects.
Dont’ know if the render mesh is either tranformed or not, but that shouldn’t be a big problem (I think).
But I think that when transforming a (non blockified) object, its render mesh might be recalculated, and that can be slow for complex objects.
Have you tried in wireframe ? ( Maybe deleting render meshes first ).
Yes, same.
@Gijs
In case you have read this…
I know the example geometry is not good, but reveals a weak point in Rhino.
And I think it’s worth investigating the issue.
What do you say?
I don’t know if it is worth it, would have to look at the file first. But if what I see in your video is a SubD, then I think you are doing something with SubD beyond the scope it was designed for. The geometry you are showing can and should be represented with way, way less faces.
FYI In the latest Rhino SRC some optimizations have been done. With large architectural models that I have tested it with, Rhino 8 performs faster now than Rhino 7 in Wireframe, Shaded and Ghosted mode.
Curve drawing has also been improved quite a bit and is now close to Rhino 7’s performance.
Yes, I do.
But that’s not the point.
Same is with a heavy mesh.
A simple move takes “forever”.