Animations 7 mchines give one light level 15 another

[maxl]

No its not an authorisation issue before evey one says....

Okay rendering an animation on an assortment of abort 25 machines, 18 of them render a consistent brightness and the other 7 render a consistent brightness unfortunately the two sets are not consistent with each other!

If we lower the light level in the scene by 20% the problem goes away?

The main differences between the two sets of machines are the the directx versions is 8.1 on the 7 machines, the version is lower on the others, does directx have a part to play in rendering with Vray?

The other is that the 7 machines are P4 xeons and the others are P3 zeons and bellow, could the pentium instruction set affect it.

The last main diffence is that the 7 machines have Nvidia Quotro 2 Pro cards in can the graphics card alter the render?

[RErender]

Are you running Max 4 with the sse optimized drivers by any chance?

[maxl]

Max 4.2 with software z buffer, I tried maxetreme and opengl for the nvidia cards but made no difference ..SSE?

[RErender]

In the Max4 root there is a "drivers" folder it contains a couple of hdi files, in another folder (been a while since I've looked at a max4 install) that is called "sse optimization" (or something like that) that also contains hdi files, If the the ones in the drivers folder were replaced with the optimized ones you can get the light value issue you are having when usng mixed CPU types.