Cycles speed regression in 2.74 RC2 (CPU only) #44046

New Issue

Mohammad Eideh · 2015-03-19T18:48:56+01:00

Mohammad Eideh commented

2015-03-19 18:48:56 +01:00

System Information
Win 7 x64 SP1 - i7 4770k - GTX 780 Ti

Blender Version
Broken: 2.74 RC2
Worked: 2.73

I was doing some tests in 2.74 RC2 and it seems that CPU rendering speed in Cycles is slower than 2.73a, as shown in the screens below. Also note the higher memory usage and peak for 2.74. On the GPU, 2.74 was only 5 seconds slower.

2.73a
19:52.87
mem: 405.74M - peak: 406.02M

2.74 RC2
22:00.19
mem: 472.34M - peak: 472.62M

Exact steps for others to reproduce the error
The blend file is part of an ongoing project/competition so I'd rather send the file directly to developers. I already uploaded the file somewhere and PM'ed the link to DingTo on BA.
Once you guys have it just hit F12 and you're good to go. Textures are all packed in.

**System Information** Win 7 x64 SP1 - i7 4770k - GTX 780 Ti **Blender Version** Broken: 2.74 RC2 Worked: 2.73 I was doing some tests in 2.74 RC2 and it seems that CPU rendering speed in Cycles is slower than 2.73a, as shown in the screens below. Also note the higher memory usage and peak for 2.74. On the GPU, 2.74 was only 5 seconds slower. **2.73a** *19:52.87* mem: 405.74M - peak: 406.02M ![Joeka9H.jpg](https://archive.blender.org/developer/F153202/Joeka9H.jpg) **2.74 RC2** *22:00.19* mem: 472.34M - peak: 472.62M ![bAxnB2D.jpg](https://archive.blender.org/developer/F153204/bAxnB2D.jpg) **Exact steps for others to reproduce the error** The blend file is part of an ongoing project/competition so I'd rather send the file directly to developers. I already uploaded the file somewhere and PM'ed the link to DingTo on BA. Once you guys have it just hit F12 and you're good to go. Textures are all packed in.

Mohammad Eideh commented

2015-03-19 18:48:56 +01:00

Changed status to: 'Open'

Mohammad Eideh commented

2015-03-19 18:48:56 +01:00

Added subscriber: @quacker

TARDISMaker-2 commented

2015-03-19 18:58:44 +01:00

Added subscriber: @TARDISMaker-2

Thomas Dinges commented

2015-03-20 00:54:38 +01:00

Added subscriber: @ThomasDinges

Thomas Dinges commented

2015-03-20 00:54:38 +01:00

Thanks for posting this, I got the file. Will check.

Thomas Dinges commented

2015-03-21 18:33:33 +01:00

Ok, I checked the file, rendered only 50% image resolution though, apart from that no changes were made.

2.73a: 7:33min, Peak 423.44M
2.74 RC2: 7:32min, Peak 490.04M

So I can confirm the memory increase, which is probably caused by the QBVH, but no speed regression. I tested this on Linux x64 with a i5-3570 (Ivy Bridge). Maybe it's a AVX2 related issue?

Edit: Same test on my Macbook with a Haswell CPU (AVX2):
2.73a: 6:08min, Peak 423.58M
2.74 RC2: 5:47min, Peak 490.18M

Here it's even faster.

Ok, I checked the file, rendered only 50% image resolution though, apart from that no changes were made. 2.73a: 7:33min, Peak 423.44M 2.74 RC2: 7:32min, Peak 490.04M So I can confirm the memory increase, which is probably caused by the QBVH, but no speed regression. I tested this on Linux x64 with a i5-3570 (Ivy Bridge). Maybe it's a AVX2 related issue? Edit: Same test on my Macbook with a Haswell CPU (AVX2): 2.73a: 6:08min, Peak 423.58M 2.74 RC2: 5:47min, Peak 490.18M Here it's even faster.

mathieu menuet commented

2015-03-21 20:48:31 +01:00

Added subscriber: @bliblubli

mathieu menuet commented

2015-03-21 20:48:31 +01:00

Maybe it's only on Windows 7 x64 then? Every scene I render on 7 is also slower with 2.74 than with 2.73 on my PC (Ivy Bridge CPU)

Mohammad Eideh commented

2015-03-21 20:59:14 +01:00

Interesting results @dingto. I was also wondering if it's a Windows related issue. Anyway, I disabled hair in the scene, set resolution at 50% and re-ran the test again:

2.73a: 04:47:28. Peak: 186.39m
2.74 RC2: 04:56:28. Peak: 188.8m

So hair/particles seem to be the culprit for the memory increase. Render is still slower but the difference is less.

Interesting results @dingto. I was also wondering if it's a Windows related issue. Anyway, I disabled hair in the scene, set resolution at 50% and re-ran the test again: *2.73a*: 04:47:28. *Peak*: 186.39m *2.74 RC2*: 04:56:28. *Peak*: 188.8m So hair/particles seem to be the culprit for the memory increase. Render is still slower but the difference is less.

Sergey Sharybin commented

2015-03-24 09:17:19 +01:00

Added subscriber: @Sergey

Sergey Sharybin commented

2015-03-24 09:17:19 +01:00

This seems to be msvc-specific because on my desktop with linux i've got about 5% speedup. On my laptop with same linux it was like 2% speed loss (which could be expected ebcause of QBVH, which is less cache-friendly). But on the same laptop and windows 7 it was about same 10% speed loss. What's more interesting, rendering on windows took much longer than on linux in both tests (and t's the same hardware).

Sergey Sharybin self-assigned this 2015-03-24 09:17:28 +01:00

blender-admin commented

2015-04-08 15:47:25 +02:00

This issue was referenced by bf11e362c5

This issue was referenced by bf11e362c5418ec40dc0437d329efceb225eb5ef

Sergey Sharybin commented

2015-04-08 15:48:00 +02:00

Changed status from 'Open' to: 'Resolved'

Sergey Sharybin closed this issue

2015-04-08 15:48:00 +02:00

Sergey Sharybin commented

2015-04-08 15:48:00 +02:00

Closed by commit bf11e362c5.

Closed by commit bf11e362c5.

blender-admin commented

2015-04-10 20:54:56 +02:00

This issue was referenced by blender/cycles@537cfea049

This issue was referenced by blender/cycles@537cfea0498da52e0197acef813b33945bce696c

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Cycles speed regression in 2.74 RC2 (CPU only) #44046