The computer is very silent with the fans not on full speed. The first time I even thought it had shut down when I came back in the room. I couldn't even hear it because of my footsteps. My previous computer was extremely loud, so I did everything to prevent that this time. The case has one 140mm fan on the back and three 230mm fans in total, on the front, side and top. The CPU coolers have 92mm fans.

In the meantime I've found out that while using fractal extreme all cores are at 2,1 GHz. While using apophysis (which uses floating-point operations), the cores go to 2,4 GHz, while task manager and open hardware monitor report all 32 cores as 100% loaded. I think the OS is confused by this weird architecture.

16 GB is more than enough. What would you use 64 GB for?

In Windows 7 Pro 64-bit with FX-8150, based on my own original research, each module contains two cores spaced 4 units apart. In other words, (0,4) share a module, and so on.

(0,4)(1,5)(2,6)(3,7)

I imagine other combinations of Bulldozer processors and operating systems may be enumerated differently. You'll have to experiment with different bit patterns and see which is fastest. With fractal Extreme, setting affinity to (0,1,2,3) or (4,5,6,7) is about 20% faster than setting all evens or all odds, so that is where I get my info. They may very well enumerate differently on your dual Opterons. Also, Microsoft still has not released the microcode update patch for the Bulldozer platform, so Windows 7 will not yet perform load-leveling optimization by threading empty modules first like it knows to do for Intel's hyper-threads. That is one highly plausible reason why Intel's charts are currently further ahead than they should be in benchmarks. If you have a program that only uses 16 out of 32 available threads, it may be beneficial to arrange them so that each thread gets it's own module, or else they will randomly collide by filling up some modules and leaving others vacant. The performance penalty will be especially significant with floating point operations.

In case anyone is interested, I made what was going to be a small presentation of the computer.
<a href="http://www.youtube.com/v/Vcl38JXg2T0&rel=1&fs=1&hd=1" target="_blank">http://www.youtube.com/v/Vcl38JXg2T0&rel=1&fs=1&hd=1</a>