Windows 7 Pro 64-bit Service Pack 1
Intel I7-4770K 3.5ghz - 8gig RAM
Nvidia GeForce GTX 760 - driver 334.89
Broken: 2.71 official - hash 9337574
The BMW test file gives different results in Blender 2.71 as compared to Blender 2.70 or 2.69
The difference(s) can be seen in the detail of the wheels. In particular, the wheel bolts, the disc brake rotor and/or shadowing are different in the latest render.
Note that I do not know if these differences represent an actual performance bug or simply a result due to changes in other Blender functions.
Please investigate. Thank you.