http://www.unixgods.org/~tilo/Opteron_vs_G5.html
И выводом:
Having said all that, I'm still not sure what to buy. From the hardware side and the architecture, I'd say it's a clear win for the Opteron, considering at a dual-CPU system.
But as I intend to run some sort of UNIX on it, and knowing that this is a complete new architecture and CPU, I hesitate, because I know the open-source developers will need some time to get the LINUX or BSD kernels and applications running stable in 64bit mode on Opterons.
Apple on the other hand has a whole lot of applications already on the market - and although i don't like their GUI, I have to give them credit for the ease-of-use of most of their applications. On top of that IBM recently released their PowerPC 970 compiler for LINUX and OS X.
So here I am.. still puzzled about what to buy..