I have a cluster of twenty (Mac Pros) with each machine consisting of two hex-core xeons in an smp configuration.  I am using SUSE 11.2 and the boxes are connected by both gigabit ethernet and 10g myrinet cards (hpmpi uses a private network over the myrinet and a 10g ultra low latency switch).  My problem is that castep (well materials studio) recognizes the number of cores on the cpu as 12.  Presumably this is due to Intel's use of hyper threading technology -- there *are* only six physical cores on each cpu.  The error on the part of the copy protection results in using twice as many licenses are I was told would be necessary.  Is there some simple fix I can use to get around this problem.  I would consider having to turn off hyper threading, but I have no idea how to do so and as this is pretty clearly a bug in Materials Studio (they allow up to eight cores per cpu I am told by the vendor), there should be some way to fix it without breaking my machines to get it to run as spec'd.  Any suggestions would be most welcome.