Ok no one ever tests BVH performance and maybe this will help the devs when they try to optimize BVH.
So Here is my result of the test file.
CPU FX-8350 4.3 GHZ
WIN 10 x64
Blender 2.73a
Time : 00:35.21
Peak Memory : 1220.52 MB
ubuntu 14.04
i7-4930k 4.5ghz
blender 2.73a (official)
peak 1310.87
time 00:05.40
optimized master
peak 1310.87
time 00:04.55
I knew my AMD was behind in BVH but I didnt know it was that bad holy crap xD
Computer 1:
CPU Intel Core i7 4770 @3.4ghz (non-oc) / RAM 8gb 1600mhz / Xubuntu 13.10 64bits / Blender 2.73a 64bits official
Render time: 00:08.18 / Memory Peak: 1220.52M
Computer 2:
CPU Intel Core i7 4790K @4.0ghz (non-oc) / RAM 32gb 1600mhz / Windows 8.1 64bits / Blender 2.73a 64 bits official
Render time: 00:13.42 / Memory Peak: 1220.52M
Computer 3:
Imac late 2012 / CPU Intel Core i7 3770 @3.4ghz (non-oc) / RAM 32gb 1600mhz / OSX 10.10.2 / Blender 2.73a 64bits official
Render time: 00:08.49 / Memory Peak: 1220.52M
I would like to ask: What’s the f*** problem? I know that on Windows, CPU performances are the weakest, but I did never see a difference that big. From what I experienced, Windows should be around 20% slower when using the same CPU compare to OSX or Xubuntu.
Even when using BI, my comp with the 4.0ghz CPU is the fastest compare to the other Comps I have. You can say that’s normal, but when you know that Blender on Win runs 20% slower when using the CPU, you can doubt a little. And here, that’s definitely not 20% slower…
I hate to ask but could you do these again and get the amount of memory they used 
BTW thanks for doing it on 3 machines and 3 operating systems 
I edited my previous post. Memory Peak at 1220.52M on both computers.
Thanks
i7-2600k O.C. @4.0ghz
Win 7 64bit
time: 00:13.10
peak mem: 1220.52M
i7-2600k
Win 7 64bit
time: 00:15.80
peak mem: 1220.52M
Ubuntu 14.04
time: 00:08.30
peak mem: 1220.52M
Crazy difference…
FX 8350 4.0 Ghz
Ubuntu 14.04
Gooseberry branch
Time 00:07:77
Peak 1310.87M
CPU I7 5820k 4.1 (OC) GHZ
WIN 7 x64
Blender 2.73a
Time : 00:11.51
Peak Memory : 1220.52 MB
CPU i3-3120M 2.5 GHZ
WIN 8 x64
Blender 2.73a
Time : 00:29.03
Peak Memory : 1220.52 MB
Blender 2.73 Gooseberry Branch
Time : 00:26.96
Peak Memory : 1310.99 MB
i7 4790k Stock
Win 8.1 x64
These times are all cray cray we need someone (smarter than me) to look in to this lol
Opensuse 13.2/64
Intel i5 3770K
Blender 2.73a
Blender latest Master build, woot. 
Cheers, mib
Master uses a lot more memory
Well thats interesting… ~28 seconds faster on your FX 8350 with a lower clock. i cri
Time: 00:09.15
Peak: 1310.87 Mb
Blender v2.73.9
Computer spec: see signature 
why are all these times sooo different lol
So I benched this scene in both Windows and Linux on the same machine…
CPU: FX-8350 4.0 GHz
Windows 7 Professional x64
Blender 2.73a
Time : 00:34.22
Peak Memory : 1220.52 MB
Ubuntu 14.04 x64
Blender 2.73a
Time : 00:08.85
Peak Memory : 1220.52 MB
Conclusion: the official build of 2.73a is significantly slower in Windows.
Recommendation: install Linux.