FreeBSD 9.0-RELEASE on PowerMac Dual G5

[Kevin H. Patterson]

Hello,

I've taken an interest lately in running FreeBSD on the powerpc64 architecture. I have access to a dual 2.5 GHz PowerMac G5, and I've successfully got FreeBSD 9.0-RELEASE up and running on it.

Only one thing seems amiss so far... it feels *very* SLOW. I realize this is an older machine, but it feels much too slow for a dual G5. Compiling seems to take forever, and top shows ~50% or more "system" CPU usage when doing almost anything other than sitting idle. Furthermore, the system fans never speed up, but run at the lowest speed even when the system is under full load. I have tried both enabling and disabling powerd support, with no effect.

For a quick sanity check, I installed ubench (0.32) from ports. The numbers were quite disappointing: 109870 CPU / 50527 MEM multiprocessor, and 55433 CPU / 30863 MEM single-processor.

For comparison, I ran ubench (0.32 from MacPorts) under Mac OS X 10.5.8 on the same machine. This time, the fans do ramp up, and the numbers are *WAY* better: 277207 CPU / 317119 MEM multi-processor, and 141021 CPU / 284113 MEM single-processor.

As you can see, all is not well. I am wondering what is slowing FreeBSD down on this machine. I have tried both GENERIC and my own kernel config. It feels like the CPU and or bus speed is clocked down perhaps to the most energy-saving level. Maybe this is where openfirmware leaves it after boot? Also interesting is to note the drastic *single-processor* ubench difference between macosx and freebsd. To me this looks like a low clock-speed smoking gun.

I also noticed that the kernel build includes flags like -msoft-float and -mno-altivec... 

I am interested in any build or config tweaks that might be in order. I am also more than happy to debug and get to the bottom of this. Any ideas?

Sincerely,

Kevin H. Patterson
KHPtech

kevpatt at khptech.com