Slow performance with one of two power supplies powered

[Craig Leres]

I have two Supermicro X9SRi-F systems that are nearly identical. Both 
have dual power supplies fed from building and generator power. One is 
acting normally but the other does not have building power due to 
electrical work this weekend and has really poor performance. For 
example running wc on a 2.5M line file takes 2 seconds on the good 
system and 40 on the bad.

Last time I ran into this I found the system was underclocking and 
"sysctl dev.cpu.0.freq" would report a lower than expected value. I 
solved this by running powerd with this config:

     powerd_enable="YES"
     powerd_flags="-a max -b max -n max"

In this case dev.cpu.0.freq is reported as 2201 for both systems which 
seems correct for the 2.20GHz Intel E5-2660 processors in use. Running 
powerd does not change the reported frequency nor does it improve 
performance.

I have another pair of X9SRi-F systems with the same power situation. 
They have 3.00GHz E5-2637 and the one running on one of two power 
supplies was reporting dev.cpu.0.freq as 1200 before running powerd and 
3001 after. The single powered system also has  lower performance, the 
wc test takes 14 seconds, the fully powered system takes < 0.5.

How do I solve this? dmidecode reports the power supplies as PWS-406P-1R 
which is rated for 400W so I think they are beefy enough to run a single 
E5-2660, memory, and a couple of SSDs.

		Craig