Excruciating slowness

[Anonymous]

i7-7700K @ 4.2GHz, 32GB DDR4-3200, nvidia rtx 2080

[edit: On Windows 10] When I set up a fairly basic design, 360 rapidly descends into taking 10s of seconds to complete adding construction straight lines and minutes to add a construction elipse... ?

I did a full clean reinstall of 360 without any plugins or anything on my [edit: secondary] Windows 11 test rig in-case it was something with my setup.

apocelipse (screencast.com)

It *all* seems to be on one cpu-thread/core too.

Are parts of Fusion written in Python or something?

This question brought to you by *6 minutes to add an elipse*.

6 minute elipse (screencast.com)

[jhackney1972]

You have read this post about running Fusion 360 on Windows 11?

[Anonymous]

Before I answer that, did you read my question?

[jhackney1972]

Yep, I sure did.  Since you cannot install A360, I assume you are saying you install Fusion 360 on a Windows 11 computer.  You do not have to answer anything for me, I am only trying to point out Autodesk's position on Fusion 360 installation on Windows 11.

[Anonymous]

I am running Fusion 360 under Windows 10. I used a spare machine that is coincidentally running Windows 11 for an independent replication on similar hardware, and I only mention it in my question because that's the machine I *happened* to use for my two videos.

[Anonymous]

What do you mean by "Since you cannot install A360"? I feel like I'm giving you a bad day 😞

[Anonymous]

Ok - I see: I removed the leading "A" from "360".

[jhackney1972]

I only comment on what I read.  A360 is the Web Database for Fusion 360 so it cannot be installed.  Your question is fully of misleading terms and statements.  If you want to reader, of your post, to take you seriously, you need to be clear and concise in the wording of your statement.

[Anonymous]

While I acknowledge I was not explicit that Windows 11 was merely the os where I replicated my Windows 10 experience, "A360" was merely a typo. I've been working with an unrelated tool called A360 for 7 years.

[jeff_strater · Accepted solution]

thanks for sharing the screencasts, @Anonymous - I'm currently on vacation, but I have sent a link to the sketch team to take a look, and see if they can reproduce it locally.  My guess is that this is pretty specific, somehow, to this sketch, but we'll verify.

Regarding threading:  Almost all of the geometric modeling algorithms, having been developed in the years before multithreading became common, are inherently single-threaded.  Until an entire new generation of solid, surface and sketch algorithms become available, this is just the way it is.  The same is true for any CAD modeler, as far as I know.

[TrippyLighting]

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@jeff_strater wrote:

  The same is true for any CAD modeler, as far as I know.

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It is a common misunderstanding amongst many users that all algorithms lend themselves equally to work  parallelized or multi threaded. That isn't really the case. Math is in the way 😉 

[TheCADWhisperer]

What is this little piece here?

Why does this Vertical line show as unconstrained?  (In the second video.)

The other end of it appears to be connected to a constrained line and Perpendicular?

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Watching the video again - I just noticed this half way up the line that I question.

I was attempting to reproduce the issue from scratch - but I normally work with fully defined geometry...

[Anonymous]

Conversely, seeing 18% cpu usage on a single core/thread for the duration of the delay could also indicate that a single something is happening as opposed to multiple somethings. Typically indicates something blocking eg on thread interaction (which seems unlikely given its a single cpu-thread), blocking operations like network, disk or memory allocation. Maybe it's trying to log something 🙂

[Anonymous]

No qualms on the threading, not where I was going, actually about what isn't happening. Being pinned to a cpu core for 6 minutes at only 18% usage I have usually found mean't something stuck in a malloc/free loop, or when CPython is involved, a reasonable path that suddenly gets unexpectedly recursed and the cpython OP_CALL overhead destroys performance.

[Anonymous]

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@TheCADWhisperer wrote:

What is this little piece here?

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That's the sketch I was trying to rush out when the wait for an ellipse got to be enough to goad me into trying to trying to create a minimal reproduction.

Attached that sketch.

[Anonymous]

BTW: The first sketch was part of an attempt to create an MVCE. The second sketch was just the most recent sketch it happened in where construction ellipse rendering became so awfully slow.

Non-construction circles? Not a problem.
Construction elipse? Time to troll Blue Origin fans by asking "how do they plan to reach orbit if you have to climb 8 flights of stairs just to reach the capsule".

[TheCADWhisperer]

Are you aware of the implications of Offset Ellipse (true Ellipse vs equal distance Spline)?

When you offset near an axis - a true ellipse is created (not equal distance).

When you offset away from the major or minor axis an equal distance spline is created.

This could all be significantly simplified by using the new Thin Feature Extrude.

(The slow sketch Ellipse issue is interesting though.)

[Anonymous]

I was not, that's super helpful; but if you take those extremities off that sketch, you still experience the construction-ellipse slowdown. I realize there are other oddities with that sketch, but that's because I'd just iterated on the design from a 90-degree angle shoulder to curving it up and over.

[TheCADWhisperer]

It is probably best not to trim (or offset) Ellipse as the Fusion sketcher has a lot of trouble with Ellipse.

I have found that it seems a lot of trial-and-error to get stuff to work seems to leave behind unseen detritus that confuses the sketcher.

Note that my sketch is about as simple as it could possibly be.

[Anonymous]

But there's no trim in the self-contained, minimal reproduction case: apocelipse (screencast.com)