[Bf-committers] Cycles performance

[Mike Pan]

Not to start another OS debate. But...

I noticed that the performance of Cycles is very OS-dependent. With the old
rendering engine, the OS can influence the rendering time by ~10%. But with
Cycles, i am seeing a huge difference in performance between Windows and
Linux/Mac, where Linux/Mac is often twice as fast.

This cleaned up chart by
Olivier<http://oenvoyage.wordpress.com/2012/02/25/blender-cycles-best-hardware-using-the-benchmark-spreadsheet-analysis/>clearly
shows the discrepancy:
http://oenvoyage.files.wordpress.com/2012/02/benchmark_win_linux.png

I've done my own dual-boot test and the results as as follows:

Cycles Render: (huge difference in render time)
OS X: 3:27
Win 7: 6:14

Classic Render: (similar time, as expected)
OS X: 1:24
Win 7: 1:29

Both OS are running natively (not under virtual machine), using the 64bit
version of Blender 2.62.

My question is, Is there any technical reason behind this? thread
management? malloc overhead?

Mike