Have I been stitched up with my new computer?

Hey guys, I have bought a new computer because the old one wasn’t cut out for blender but this new one doesn’t seem much better than my crappy old laptop. I’m no wiz with hardware. I bought a ryzen 7 2700x with 32 gb ram, GTX 1660 and SSD. Average setup but I thought it would be able to run a simple cloth simulation no problem. Could there be something I’m doing wrong with settings or something? Can someone help this noob out?
Cheers :call_me_hand:

How many vertices is your cloth? The more vertices the slower. Cloth simulation in blender is slow. It’s why they don’t use it for main stream games yet.

What was the specifications of your old machine? Was there much difference in the score comparing your old CPU and the new CPU in this list?

You share the .blend file and we would be able to analyze the problem.

If the cloth simulation is a single threaded process, it may not be that much of an upgrade though. If you want to be sure you’ve got a significant upgrade, then compare the CPU rendertimes in Cycles instead.

Generally, newer CPUs bring just relatively small % improvements in core clocks speed, but they usually bring more cores and more threads. Single threaded processes utilize only single thread on a single core, so you will see only that small % improvement. I am not sure cloth simulation in Blender is a single threaded affair, but I’d expect that to be the case since cloth simulation is notoriously difficult to multithread.

2700 verts, works fine until I put on self collision. It then pauses and bad things happen

My old comp sits at 1800 and the new one at 2185 on that list. A bit depressing scrolling down that list to find my new computer

But with bad things you mean performance/speed problems, or poor simulation quality.
Without the .blend file we cannot be very helpful.

Apparently new users can’t upload files sorry. Thanks for all your responses.

bad things means screen goes grey and says blender is not responding.

If the size is less than 30MB, upload the file here, then share the link:

Or you can use google drive or dropbox, or some other service.


Just the first steps of a cloth sim really. See how she runs on your computer.

Ryzen 5 2600 here, 16 GB RAM, clothsim crawls, unusable.

Your settings are too optimistic :). Lower collision quality to 1, self collision distance to 0.01 or lower. This gives me about 8 fps. Try those, then work your way up. I don’t know much about blender’s simulations, though, so my advice might be nonsense, but that’s what I found.

Btw, I noticed that my 12 threads are all active during the simulation, but no thread is at full power, only about a quarter. Interesting.

Sometimes it does really strange things when play animation. I think I’ve seen this problem before in 2.80 if the simulation hasn’t been baked. If you previously “bake” the simulation from the Cache item in the properties panel on the right, does it work correctly for you?

Mmm, sometimes strange things also happen with baked simulation.
Here is how it looks when it does not do strange things on my machine (i7 3770 - Blender 2.80 - Linux):

but sometimes it does this:

Can you test on your machine with Blender 2.81 from buildbot builds:

This is also happening on my machine with 2.81. @Razmus , could you report the problem in bug tracker and sharing the .blend file with developers?

Yes, it is common for this to happen in Blender simulations. It’s strange, I’m not an expert, but my experience tells me that in Blender Single thread performance is always important, even for those processes that are multi thread like simulations. In some particle benchmark that was out there, my times were better than those users with CPUs that had more threads than my CPU, but worse single thread performance.

Ah, I see, thanks YAFU, good to know.

Thanks Sanne, Yeah I had started at the base load but it didnt result in adequate self collision to get the result I was after. I also noticed that my computer doesnt actually sound like its working very hard to run the sim.

Thanks for your help YAFU. Its really temperamental, I actually ran it again just then and it worked really well once but now doesn’t work again so must be a bug. I will send report to the devs.

Let me know what the link to the report is when you do it.