Decline in performance, an increase of over 209% in the rendering
Closed, ResolvedPublic


System Information
Lubuntu 16.04 Intel HD 5500
Ram 4GB

Blender Version
Broken: ( 2.78.4 d426c335c5)
Worked: (2.78c e92f2352830)

Hi, with the latest build there was a noticeable decrease in performance, I hope you all come back as fast as before.



Hi, can you please add your test file?
Did you check with official benchmark files from


Here the test with the BMW model, even with this scene shows a considerable increase in the rendering time with CPU.

CPU Blender : 2.78c e92f2352830
RenderTime 24:02.50

CPU Blender : 2.78.4 d426c335c5
RenderTime 42:40.21

While with my little GTX750Ti there is a slight increase in speed.

GPU Blender : 2.78c e92f2352830
RenderTime 09:32.60

GPU Blender : 2.78.4 d426c335c5
RenderTime 08:56.60

Can you please attach your system info?

Blender --> Info Editor --> Help --> System info.

Looking at our own tests: there is not that big of a slow down maybe ~5seconds so the bug might be with a particular cpu kernel.

Here the details of my system.

hmm... CPU device capabilities returned nothing. Can you try with factory settings, both testing performance and the system-info?

Aaron Carlisle (Blendify) triaged this task as Incomplete priority.Apr 8 2017, 8:03 PM

Factory settings doesn't affect CPU device capabilities as far as I know.

This is using a 32bit daily build, I guess the 2.78c you're comparing with was also 32 bit? If so, perhaps it's related to rBced8fff5de0f.

@Brecht Van Lommel (brecht) Hi, I don't use a 32bit version, below the test asked me to do, with factory settings and info.

The system info indicates you are using a 32 bit version (i686) though, so I think you might have downloaded the wrong build from

@Brecht Van Lommel (brecht) you're right, now I download the new of today, do not know how the hell did I go wrong, I'm sorry to have made you waste time unnecessarily I apologize strongly.

Aaron Carlisle (Blendify) closed this task as Resolved.Apr 8 2017, 9:29 PM
Aaron Carlisle (Blendify) claimed this task.

No problem, thanks for testing. Still kind of interesting that the 32 bit build is so much slower.