Questions tagged [performance]

Questions pertaining to software performance or computational speed of Blender should use this tag. (Do not ask hardware specific questions. They are considered off-topic)

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24
votes
4answers
13k views

Cycles hybrid rendering

The Cycles render engine can render both on the CPU and the GPU. I often render over-night so I do not need my computer to be responsive. Is it possible to render with Cycles using both the CPU and ...
24
votes
6answers
17k views

How to make VSE render faster?

I'm putting together a video from the VSE. In the sequencer window it is rendering and scrubbing at near realtime yet during output it is taking around 3x longer. The frames are taking 0.13 seconds ...
23
votes
1answer
7k views

Python performance with Blender operators

In my script, I have for loop over many cube objects (~1000) and the treatment is very slow. Looking more in details, I notice that in the same amount of loops: if ...
19
votes
3answers
31k views

How will multiple GPUs improve Cycles' rendering performance?

I have an NVIDIA Titan GPU and I'm able to add another card, but I wonder whether Blender will benefit from more than one GPUs? Should I do it as SLI or should I just do it as an added card? I just ...
18
votes
5answers
5k views

Why/how does tile size effect performance?

The general wisdom is "for CPU use 32x32 tiles, for GPU use 128x128 or bigger, depending on your card". But why? Why should a ...
17
votes
4answers
22k views

How to configure blender so that it uses only 50% of total CPU when rendering?

I need to render a very computer-intensive scene using cycles and for some reasons, I decided to use my home computer (i5 3.30 Ghz, 10 GB RAM, 2TB Hard Drive) to render it. However, the problem is ...
16
votes
1answer
12k views

What does static/dynamic BVH do?

In the render properties panel, under the performance rollout there is a setting for static vs. dynamic BVH. I am simply wondering what this setting does. From the Wiki: The raytracing ...
15
votes
1answer
9k views

Why is my cycles render still grainy on 1000 cycles?

I recently made a desk lamp model and set the samples to 1000 for an overnight render upon waking up the image was still rather grainy is this something in my blender that isnt set right or something ...
13
votes
1answer
16k views

What's the difference between the various Open Subdiv compute types?

It seems there are 5 different available "compute types". what are these compute types? What's the difference between them?
12
votes
6answers
890 views

How to find the number of loose parts with Blender's Python API?

I want to find out how many loose parts a mesh has using Python, i.e. write a function that takes a mesh object as an argument and returns an int. So far I haven't found a way to access this ...
11
votes
3answers
5k views

Should I wait when Blender isn't responding?

By error I placed the angle of the smart uv unwrap to 1 and now Blender is not responding. I guess it calculates the uv. The problem is that I have a lot of unsaved changes on the mesh. Should I wait ...
11
votes
3answers
10k views

Why is rendered viewport faster than rendering individual frames?

When I'm using rendered viewport it initially takes a while before rendering starts, but once it does, I can freely move around and rendering a new view happens almost instantaneously. When on the ...
10
votes
6answers
36k views

Best Tile Size for Blender Internal Renderer and Cycles

There've been a few discussions about tile sizes for Cycles, but none that I can find about that of BI. Since it renders with the CPU, does it follow the same rule as cycles where smaller is better (...
10
votes
3answers
5k views

Is Physics calculation multithreading possible?

Is there a way to turn on multithreading to make use of all of my computers cores for simulations? I am running on a monster of a machine, but without utilizing all of the cores, physics simulations ...
9
votes
1answer
2k views

How to efficiently instantiate object with memory-hungry modifiers?

Using Alt + D to duplicate light meshes with heavy modifiers (like a leaf with a particle instance modifier or a trunk with a subdivision modifier) can lead to huge memory usage. Because only the base ...
8
votes
4answers
4k views

Blender becomes very slow with large amount of objects sharing mesh data

In my script I am importing a large amount of objects (+2500) but sharing the mesh data from one single primitive. While this has taken care of importing speed, it completely slows blender down. ...
8
votes
3answers
2k views

Managing/Reducing noise in a night scene

I've been trying to get a pretty noise free image from this scene for a while. And nothing seems to be working. I've been trying to use 3000 samples, then rendering different noise seeds and composite ...
8
votes
2answers
2k views

What are the advantages of turning on “cache BVH”?

What are the advantages of turning on cache BVH for a cycles render? Not sure how to elaborate. I'm not necessarily looking for a technical description, just a better idea for when to use it, and ...
8
votes
1answer
9k views

What is Clamp Direct/Indirect?

What does the "Clamp Direct" and Indirect values mean? I may seem silly but i'm really new to blender. Could you please tell me what are they useful for? Thanks!
8
votes
2answers
354 views

Performance of mixing colors vs mixing colored shaders

Is there a performance difference between these two setups? I imagine on a material this simple, there's not going to be much of a difference. But on a complex material, it could. If you had a choice ...
8
votes
1answer
2k views

Working with high polycounts?

I'm importing meshes to do some retopologisation on but blender just can't handle it without me having some sort of quadro card. Do I have to use mudbox or something similar to do work with such poly ...
7
votes
5answers
3k views

Is it possible to render a movie on a single computer in blender?

Is it possible to render a fairly graphical movie on a decent gaming-computer, with a GTX graphics-card, 4 2 GHz core CPU and 8 GB of RAM, or do you need to have a gigantic rendering-farm like Disney? ...
7
votes
2answers
2k views

Are there any ways to speed up blender compositor?

I have switched companies for a while, while in my last company we where using Fusion for compositing, in the new one we are using Blender. I find it a bit hard to transition because of 2 main ...
7
votes
1answer
9k views

Is it possible to use different CUDA-capable graphic cards to render simultaneously?

I know that you can't mix different spec cards for SLI gaming, but I suspect that when it comes to 3D rendering, the renderer will simply divide the work up automatically. Choosing the optimum tile ...
7
votes
3answers
20k views

How can I tell if Blender is using all 64 GB of RAM?

I have 64GB of RAM on my computer and I'm trying to check if Blender is using all that it can. I still get viewport slowdown at times when working with complex objects. I know there are many ...
7
votes
1answer
914 views

Render FPS is low

I looked at the other questions about this, but I'm finding no solution. Partly because I have the newest blender version, 2.76. I am playing my animation back, and it plays around 5 fps. I am using ...
7
votes
2answers
521 views

Are there any disadvantages to starting blender with the --enable-new-depsgraph argument?

The question says it all :). I'm asking because it solved the latency problem between parents and children in the viewport and I will use this as the default blender starting argument (blender --...
7
votes
2answers
299 views

How can I prevent blender from doing ridiculously large calculations?

Occasionally I end up using a metaball. If I scale the main metaball, it changes the resolution. The smaller it gets, the high resolution it becomes. If you press S to make it bigger and you ...
7
votes
1answer
2k views

Does Blender have a way to reduce texture size?

I have several objects, each with 1024x1024 textures on them. I want to reduce that to just 64x64 per object, for performance reasons (I'm planning on having a lot of these objects). I'm not worried ...
6
votes
2answers
3k views

Blender Global undo is very slow on complex scenes

When I'm working with complex scenes (a few million polygons with +- some subdivision), say you're making a weapon highpoly model, the Blender's Global Undo becomes extremely slow. Even with simple ...
6
votes
2answers
1k views

Faster blur effect in Blender VSE

Blender's Video Sequence Editor allows you to use the Gaussian Blur effects strip to blur the image or video, however, it uses a lot of CPU and the rendering is slow like a hell. It takes around 2 ...
6
votes
1answer
3k views

Blender Cycles Slow Rendering Interior Scene

I have create a very basic blender scene with Suzanne and a modified cube with no UVs and only basic materials. The scene contains about 3 emissive lights. Using the cycles rendering engine, when ...
6
votes
2answers
10k views

OpenCL vs CUDA Rendering

Nowdays I have the old Radeon HD 6870, and it's not compatible with OpenCL, so the rendering is made by the CPU, that is a quite slow comparing with GPU rendering. I'm thinking on a upgrade to R9 380 ...
6
votes
1answer
830 views

Turn physics proccesses off and on?

Is there an easy way to, while keeping all of the physics settings the same, turn off the physics processing? Essentially, I have a huge scene with a ton of physics and I'm not ready to bake it yet ...
6
votes
1answer
115 views

Saving blend-files straight to server nets 0.5% speed of a windows file copy, how to fix?

Some context: Part of our company (about 3 fulltime people) do ArchViz, we're using Blender 2.79b and are transitioning to Blender 2.8. Tests underneath were done using 2.8. I'm not an artist myself ...
5
votes
4answers
11k views

What are the pros and cons of using Blender on Windows or Linux?

Is Blender more stable on some Linux distributions, or just on Linux at all? I am contemplating dual-booting my computer and partition some of my HDD for Linux to use blender there. Would there be any ...
5
votes
1answer
17k views

Why is my render taking so long?

My interior is rendering almost two hours and it shows only 2 samples that have been rendered. I don't quite know how to select properly those render settings to make good quality interior scene. ...
5
votes
2answers
452 views

Does Cycles use a Camera Frustum check?

So, in a random tutorial (I can't find it atm) Andrew Price mentioned that Cycles will render all geometry/particles, even if they are not visible to the camera; This suggests that Cycles doesn't use ...
5
votes
2answers
13k views

How can I improve viewport performance when using Dyntopo?

I'm doing a Blendercookie course on how to sculpt a Scifi weapon with dyntopo. The fact is that when some piece reach a certain level of compleiity (about 1.1 million tris) the systems starts to lags ...
5
votes
2answers
932 views

Maximum number of materials that can be added in a scene?

I have very large number of planes in my scene and each needs to be assigned a color, and to do that, I am assigning a material to each plane. Blender is allowing 2^15, i.e. 32768 materials. But the ...
5
votes
1answer
2k views

Screen lag during GPU rendering

GPU rendering causes some screen lag while rendering, with the amount depending on how heavy the render is. I understand this is due to the display driver being busy. What I don't get is why it ...
5
votes
1answer
705 views

Which is more efficient? duplifaces, particles, or group instances?

Particles give more controls for doing things like randomizing rotation of instances, but duplifaces and group instances allow for rotation and scale of individual instances. For something like ...
4
votes
1answer
606 views

Using two GPU video cards

Does anyone know, how can I check if I am using my two video cards? It seem Blender is using only one of them. I have checked both on the user preferences settings. But reading temperatures in GPU-Z ...
4
votes
1answer
542 views

CPU vs CUDA performance differ in render and rendered display

Blender 2.78a on archlinux (FX-8320 @ 4.4GHz, GTX1060) Rendering times for RyzenGraphic_27.blend from amd website: CPU - 0:58 CUDA - 1:20 Live rendering times ...
4
votes
1answer
2k views

VSE: How to Speed up the Preview of Image Strips?

The Issue Is there any way to speed up the preview of image strips in the video sequence editor? Unfortunately, the preview in the VSE is very choppy and indicates that it runs at only a few frames ...
4
votes
2answers
865 views

Slower Cycles Render on Faster Computer

I'm rendering the exact same file in Blender on two computers. It's an animation (here's a frame) I'm using the network rendering placeholder and non overwrite functions to render individual frames ...
4
votes
1answer
543 views

Is there a render engine with complete GPU support and Blender integration

Is there any rendering engine for Blender that only uses the GPU? I know that Cycles and Luxrender can do this but not all materials work In gpu mode. So what I am asking is are there any rendering ...
4
votes
2answers
751 views

Video Editing - System Resources not being used

I need help getting blender to use up more of my system resources to render videos as it never seem to see it use more than 30% of my CPU and my GPU stays on idle (changed settings to use cuda). It ...
4
votes
0answers
59 views

How to list all data in a blend, and how much disk space it's using? [duplicate]

I have a blend file that I've worked with for a long time, testing and experimenting with things like rigify and almost everything else. I'm trying to clean it up. By removing a lot of mocap actions, ...
3
votes
1answer
1k views

Use all Ram on Blender when rendering? (Cycles and Blender Render)

I have 32 GB Ram on my computer, how can i make Blender use all (or at least, the most) of the RAM when rendering?

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