Fusion Support
Report issues, bugs, and or unexpected behaviors you’re seeing. Share Fusion (formerly Fusion 360) issues here and get support from the community as well as the Fusion team.
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Even with a relatively beefy system, the software is slow and freezes all the time

Message 1 of 16
467 Views, 15 Replies

Even with a relatively beefy system, the software is slow and freezes all the time


I have realatively strong system (Windows 11 Pro (64-bit), AMD Ryzen 7 5700G(8 Cores, 16 Threads, Base Frequency4.30 GHz), Memory 64.00 GB DDR4 SDRAM, with AMD Radeon RTX 6700 XT GPU). Even tho my system is supposed to be enough for my hobby 3D designs, it's very laggish. Is there a setting I missed or something?Loading my project takes ~20 minutes, even just clicking on showing an object kills it for 10-15 minutes. Usually it uses only about 20-24GB of RAM, and not sure what could I do to make it more workable. I try to work with one object at a time, sometimes I convert mesh body to regular matter body to be able to incorporate to my other bodies, and usually inactivate all what isn't neccesarry to be displayed to ease the performance choke, but still very laggish... Any suggestion how to make it a bit snappyer? I tried orking without the timeline (it helped greatly before, when I used a much weaker PC) and working OFF-line mode... not sure what could I do more, are there other performance enhancer settings?
Thanks for help folks... 

Labels (4)
Message 2 of 16
in reply to: klevipostaja

Attach one of your model, you feel in lagging, so the Forum users can take a look at your model methods.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

"If you find my answer solved your question, please select the Accept Solution icon"

John Hackney

Beyond the Drafting Board

Message 3 of 16

I have a similar problem, we were experiencing poor performance so buffed the computer as far as we could, 24 core i7 processor and 128gb of RAM etc.


Sadly, it hasn't made much of a difference, I still have to wait for minutes for some things to complete, looking at the processor, I can see that only two cores really get used most of the time, it shunts around to pick a cool one fairly regularly and those two cores are running flat out but it seems that fusion isn't written in a manner that makes use of all of the processing power available to it.


Interestingly, RAM seems to be different, I have seen significant improvement in performance when I moved from 64gb to 128gb, although I don't think I've seen it use more than 50gb.


I found that there were a few things that helped the performance a lot:


  1. Try and use as few capture positions as possible - I only recently realised that you can edit a capture position and our assemblies now only have a one per timeline.
  2. Joints are evil - For some reason assemblies with joints in seem to corrupt and slow everything down massively, rigid group doesn't seem to have as bad an effect as the others, but still doesn't help.
  3. Mesh doesn't seem to be optimised - I have a couple of models that have been converted from meshes and are tessellated, they are just slow, they get better if I reduce the complexity of them, but the number of triangles seems to just make fusion fall over.

I'm sure others will have some other good / better suggestions too which I would love to hear as well.

Message 4 of 16
in reply to: jhackney1972

I'll try to do it soon. Thanks

Message 5 of 16

Thanks  Robert-FreEnergy,

I noticed indeed, that when I tried to convert an object mesh to an editable object, it craps itself... I get it, over 10 000 triangles etc... but no way that a fairly beefy PC an't handle that! This isn't an idustrial scale model either, what would the software do if I had a complex mechanism with all the parts etc... Mostly I designed unique Catan game tyles, with a lot of mix & mach from vaious external sourses, made my own framework and such... and some other hobby level stuff... While my project is small, and only basic shapes are in it, it doesn't have any issues. As soon as I'm having 10-20 objects (most of the time I'm merging them into one to save on the resourses) and tick the eye icon to not be rendered while not in use, it doesn't have mich issue, but when I try to make it visible any of the more complex bodies, or God forbid interract (ie. merge/cut/resize/move) they usually kills it... I just didn't want to make one object, export it, then discard it completly to free resourses, as if I want to edit or use them partially later, they'll be needed toimport as mesh, and convert again... But I guess that'll be the case if I want to be able to do anything... 
Thanks for your help. I was just wondering, if there is any setting, that allows me to decrease resolution, or something to not kill the whole system, while most of the time isn't even necessary to be interacted with the majority of the project elements/bodies. ...Like Chrome does kill memory usage while the tabs are not in focus, this could also just ignore the other bodies/groups which has no relation to the currently worked on ones... I make copies of all repeating elements when I create a new tile for example, in a new group, so they newer get accidentaly merged with the wrong body, or altered in a way that others will be altered... 
I had a lot of issues sometimes when 2 bodies won't merge, eventho they're clearly intersect and they're solids... so most of the time I do it one-by-one... and end up with 2-3 bodies in separate groups. I guess I just deal whith what I get for free, not complaining... I wasn't even sure if I buy it would work, or would worth it...

Thanks anyway!

Message 6 of 16
in reply to: jhackney1972

I tried to attach it, but it's almost 600MB Not sure if it makes all of the non visible bodies into the file also, or just these 2 bodies are so huge in size... the model is about 7-10cm in diameter, with about 10mm height...

Message 7 of 16

Hmm, if the meshes that you are importing are simple, you might find it easier to create a fresh sketch using the mesh as a reference (like tracing) and work with a proper parametric model. 

Fusion works much better with those. Have you got an example model that is behaving particularly badly, I could have a go at optimising it for you if you would like?


I don't think its the rendering of the model that causes the slow down, which means resolution changes wont change anything. I think the problem is that when you adjust a body that has thousands of faces, fusion has to compute what the change means for each facet, I think it does this one calculation after another which is why it takes so long. 

Message 8 of 16
in reply to: klevipostaja

If your model is 600MB, then that is a sign that it is not a simple model at all.  Importing a mesh then converting it to BRep with the "faceted" setting is always a recipe for poor performance.  You will get much better performance if you created the objects natively in Fusion using sketches and features.  If you think you need to use meshes, then Fusion is not the right tool for you.

Jeff Strater
Engineering Director
Message 9 of 16
in reply to: klevipostaja


If you are dealing with complex meshes I recommend  Meshmixer or Blender



Message 10 of 16

@klevipostaja wrote:

sometimes I convert mesh




Mesh is rubbish.

I am surprised how many cannot visually see that.

Message 11 of 16
in reply to: jeff_strater

Fusion starts to get slow at like 30,000 facets, which is like a 2MB .stl


If your .stl is 600MB then that's like 12,000,000 triangles. Even Meshmixer will run slow on that.


I'm guessing you are working with scan data?

Message 12 of 16

@Robert-FreEnergy wrote:


I'm sure others will have some other good / better suggestions too which I would love to hear as well.

Converting a triangulated mesh directly into a solid model is a workflow that IMHO should never have been implemented. CAD works with NURBS representation under the hood. That is computationally much more involved than a mesh. When converted, every triangular facet is converted into a trimmed NURBS surface.

Modeling operations will now have to calculate hundreds, if not thousands of surface intersections, as opposed to a hand full. It is only natural that this results in performance degradation.


Also, modeling operations are in any parametric CAD system are almost all single core. So look for higher single core base and boost clock. Unless you are rendering in Fuiosn 360. then all cors are used to their max potential.


As other have noted, share a design and we can provide more targeted feedback.



Peter Doering
Message 13 of 16
in reply to: klevipostaja

Thank you all for the help, I think I found my answers... Well, I'm new to this software, and yes, used mesh, as that was the only way (if I know correctly) to import an stl into 360 and convert it to solid object to be able to work with it... (resize/cut/add etc.) I have roughly 70 objects in the project, some small, some larger in complexity... the average stl file size is 7-25MB what I import, and most of it are discarded, I just pretty much cut stuff apart, and paste, and alter... It would be waaay longer to recreate all the different elements, so I just use others... (I know... but it's for me only, and I don't want the wife to leave me for spending all my time in fron of the PC just for this... LOL) I understand now, that there are multiple factors what affects my software lags, and I think I'll just do it one-by-one... once I have an element completed, I just export it, and delete it from my project, so it'll have less stuff in it with only what I'm working on... I didn't realize, that this eats up PC perfrmance this much, I used Photoshop a lot before, and (I don't know why) I assumed that most softwares work like that... like they don't use resources, unless they're required... I'll try the other software suggestions as well, thank you, but probably I just try to follow the above advices and lower the project's complexity amongs the other solutions...

Thanks again, This is nice, to have a community like this, who's eager to help for rookies like me!

Message 14 of 16

Thanks, I see that now... I know these somewhat, but I thought these issues are starting to manifest only on large scale and more massive models and projects... I see now my flaws. As attaching I have only .obj files (as these can be used in the slicer to print it) and mainly the problem in question was around the 3D unique Catan table top game designs... I tried (somewhat succeeded) to design and print magnetically attached, nicer 3D elements of the game... There are a few on the market which I'd say if you spend money for, make it right, and that's why I did my own... As these tyles involve multiple resource map segments, like forests and other scenery, where there are many intricate elements are part of the whole, and designing/building everything from ground up would take ages and lots of effort and time, hence, I utilize other's designs, dismantling them, and building my own from those...
Thanks for contributing to my understanding of my mistakes, I learned al lot from this...
Message 15 of 16

If you are using a commercial subscription, Fusion 360 has tools that can help convert simple mechanical/prismatic mesh geometry into valid CAD models.

If you can post a few example I'll see what can be done with those tools.


These tools are only available in the paid subscription:





Peter Doering
Message 16 of 16
in reply to: klevipostaja

The problem arose with theese things... I don't think the premium would be worth it, as I'm not using it for other than occasionally making some unique casings for micro controllers or 3D print some rare solutions/experiment with solutions with puzzle building/designing...

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report