Well, I think it's obvious that E-on seriously needs to rebuild Vue4... I was going to suggest a quick test of downloading CineBench and running on both rigs... but I guess it's moot now, eh? The problem with HyperThreading is that the processor is reported to the OS as 2. If the OS is unaware of the difference between physical and logical processors, you can kiss efficient scheduling good bye. The problem is that there is only one floating point add/mul pipeline, so that particular resource is shared; if the SMP code in Vue is unaware of the difference between physical and logical processors, that would be a bottleneck, since it would likely be trying to perform simultaneous floating point ops rather than accessing memory while one thread is crunching... the net result being that it thrashes the floating point pipeline. It's probably not E-on's fault that this is a problem, it is more likely that they just haven't updated the rendering engine yet. Just for reference... rendering in Cinema4D R8.1/2 ALWAYS shows better performance with HyperThreading enabled than without.