DXF Performance Issues

[Anonymous]

Hi All,
I need to import DXFs for various items that I need to incorporate into a design. They are not complex by 2D CAD standards but F360 basically grinds to a halt as soon as I try and use them.

I have tried several of the suggestions mentioned in the forums already:

• Updating NVIDIA drivers. This took it from "F360 freezes eternally" to "F360 only takes 2-3 minutes to select sketch items after drawing a marquee" but most operations (move, delete etc) cause the program to stop responding
• Simplifying sketches. This is a marginal improvement which requires I delete critical parts of a design in order to make the software run well enough, which it still doesn't come close to.
• Hiding sketches. Yes, it helps. No, it still doesn't work well enough to use in an ongoing sense. I'm not sure how I'm supposed to lay elements of a design out when most of it is hidden.

The part that bugs me (pun intended) is that my 1.5 year old PC barely breaks 20% CPU and 15% GPU while doing this. Less than a quarter of my RAM is utilised. The PC does not appear to be running out of steam, as verified on a 13 year old machine with basically the same outcome when doing the same operations with the same files. So what's the hold-up? Am I unreasonable for expecting it keep up with DXFs that I've been using for 10+ years and never even considered performance?

[jeff_strater]

You need to understand what Fusion does with an imported DXF.  It turns it into a sketch.  That means:  constrained geometry, which must be solved.  The more entities in the sketch, the slower the solve.  AutoCAD does NOT solve its geometry, which is why it is much faster.

Can you share an example of one of these "not complex" DXFs?  I suspect that they are much more complex than you realize, at least by sketch standards.

"The part that bugs me (pun intended) is that my 1.5 year old PC barely breaks 20% CPU and 15% GPU while doing this".  This is because modern computers get their power from having multiple CPUs.  However, geometry algorithms are inherently single-threaded.  So, using 20% of the CPU probably means that one CPU is very busy, and the rest are idle.  All CAD systems have similar restrictions.  Many of these algorithms pre-date any kind of parallel processing.  We are continually working to parallelize these algorithms, but there are 30-40 years of history in those algorithms, and it will likely take a significant amount of time to do this.  Some algorithms may never be parallelizable.  Also, we have to be very careful not to break anything in this process...

[Anonymous]

You're right. I do understand that F360 treats imported DXFs as sketches, and needs to resolve the constrained geometry.

I am entirely understanding now that my DXFs, regardless of my supposition, are too complex for F360, and I don't have another constrained-geometry software package to compare it to. My hopes that I could begin to migrate my old-fashioned design ways entirely to F360 have been dashed, but it would have been unusual to assume that newer, more modern software would be technically capable of opening older formats, but fall over in doing so to any useful extent. While I'm not owed it, and seasoned F360 users are probably laughing at me, I'm not the only one who's made the mistake of approaching it from this point of view.

I appreciate your summary regarding multi-threading. While it's not necessarily the end user's obligation to understand, it does help me at least. Multi-threaded personal computing has been common for at least 15 years now.