I was wondering about render times in Blender and ways to speed it up.

Most of you may recall this page, which provides a blend file for rendering, write down the time spent and compare it with others who rendered the same scene on their computers. So I downloaded the file and started some testing.

My machine is far from being "high end" as the one figuring #1 on the list (Apple Mac Pro two Intel Xeon 3200MHz with 8 Cores, 12 seconds for render! wow... ). In 2005 it was a pretty good laptop, and it still works fine for me while I can't afford a new one. Mine has 1GB RAM, while the one on the review has only half of it.

So, let's suppose there is nothing else I can do with my Blender scene (everything is optimized, from vertex count to lights and textures) and a hardware upgrade is out of question. How much does some environment adjustments change my render speed?

I'm currently using Linux Fedora 8. Not that I gave up on Ubuntu, it's just that I like testing other distros... =)

I don't have Windows installed on my machine, so this is an 'open source only' test. ;)

For the tests I used some versions of Blender:

1. The 2.45 Linux official one that I got on blender.org;
2. The 2.45 from Fedora repositories;
3. An SVN (revision 14307) compiled by myself with some flags set for my machine ( '-march=pentium-m', '-mmmx', '-msse', '-msse2', '-mfpmath=sse');
4. The 2.45 Windows official binary, running over Wine
5. A Windows SVN optimized version compiled by Mike Pan on graphicall.org, also running with Wine.

You may ask why I used Windows versions running Wine. Well, sometime ago there was a thread on BlenderArtists.org about how fast Blender run over this layer on Linux. So, I found it valid to give it a shot too.

All renders (but one, as explained below) were made under the same circumstances: I had a minimal desktop running, with Blender as the only 'big' app opened (no web browsing, no music...). I took 3 renders with each build to make sure the results didn't vary much on the same conditions. Luckily (and pretty obviously), they didn't differ much - less than one second. I've picked the quickest ones.

Well... too much talking, right? =)

Let's take a look at the results:

1. 2.45 Official Linux build: 05:43.38
2. 2.45 Fedora build: 05:27.47
3. 2.46 Self compiled build: 04:22.05
4. 2.45 Official Windows build + Wine: 04:21.67
5. 2.46 Windows SVN + Wine: 03:45.03

I also tried I more time with my self compiled build, turning off the X server and going to the Shell as 'single user' mode to render from command line: 04:19.31

The results are quite impressive. From the official Linux build to the fastest 'Windows optimized over Wine' I could speed up the render in 2 minutes! Maybe that isn't so important when rendering stills, but when rendering animations... let's do the math for a minute of animation:

1 second = 25 frames.

1 minute = 60 x 25 = 1500 frames.

If I can save an average of 2 minutes on each frame, I can finish the entire rendering process 50 hours earlier! That's basically two days of waiting you can save!!!

So... tweak your lights, the face count, textures, get a powerful machine, but don't forget to make sure your working environment is also optimized. =)

* can anyone explain why a Windows binary over Wine runs faster than the optimized 'native' Linux build?

 

[UPDATE]

After searching for other cool flags to optimize the compile process, I was able to cut 16 seconds on the render time, going to 04:06.19.

But this is still not like the optimized Windows build over Wine. =P

[/UPDATE]