Running frequency_governors_test sheds some light on this bug because it exposes this error:

ERROR    On demand performance vs maximum of 380.0% is not within 10.0% margin

# /usr/lib/checkbox/bin/frequency_governors_test
2013-12-26 18:15:54 INFO     System Capabilites:
2013-12-26 18:15:54 INFO     -------------------------------------------------
2013-12-26 18:15:54 INFO     System has 4 cpus
2013-12-26 18:15:54 INFO     Supported CPU Frequencies: 
2013-12-26 18:15:54 INFO         2801 MHz
2013-12-26 18:15:54 INFO         2800 MHz
2013-12-26 18:15:54 INFO         2600 MHz
2013-12-26 18:15:54 INFO         2400 MHz
2013-12-26 18:15:54 INFO         2200 MHz
2013-12-26 18:15:54 INFO         2000 MHz
2013-12-26 18:15:54 INFO         1800 MHz
2013-12-26 18:15:54 INFO         1600 MHz
2013-12-26 18:15:54 INFO         1400 MHz
2013-12-26 18:15:54 INFO         1200 MHz
2013-12-26 18:15:54 INFO         1000 MHz
2013-12-26 18:15:54 INFO         800 MHz
2013-12-26 18:15:54 INFO     Supported Governors: 
2013-12-26 18:15:54 INFO         conservative
2013-12-26 18:15:54 INFO         ondemand
2013-12-26 18:15:54 INFO         userspace
2013-12-26 18:15:54 INFO         powersave
2013-12-26 18:15:54 INFO         performance
2013-12-26 18:15:54 INFO     Current governors:
2013-12-26 18:15:54 INFO         cpu0: conservative
2013-12-26 18:15:54 INFO         cpu1: conservative
2013-12-26 18:15:54 INFO         cpu2: conservative
2013-12-26 18:15:54 INFO         cpu3: conservative
2013-12-26 18:15:54 INFO     Beginning Frequency Governors Testing
2013-12-26 18:15:54 INFO     Userspace Governor Test:
2013-12-26 18:15:54 INFO     -------------------------------------------------
2013-12-26 18:15:54 INFO     Setting governor to userspace
2013-12-26 18:16:25 INFO     Setting CPU frequency to 800 MHz
2013-12-26 18:16:25 INFO     Running CPU load test...
2013-12-26 18:16:25 INFO     pid 4613's current affinity list: 0-3
2013-12-26 18:16:25 INFO     pid 4613's new affinity list: 0
2013-12-26 18:16:25 INFO     Minimum frequency load test time: 0.23
2013-12-26 18:16:25 INFO     Setting CPU frequency to 2801 MHz
2013-12-26 18:16:25 INFO     Running CPU load test...
2013-12-26 18:16:25 INFO     pid 4613's current affinity list: 0
2013-12-26 18:16:25 INFO     pid 4613's new affinity list: 0
2013-12-26 18:16:25 INFO     Maximum frequency load test time: 0.05
2013-12-26 18:16:25 INFO     Found ida flag, increasing expected speedup by 8.0%
2013-12-26 18:16:25 INFO     CPU Frequency Speed Up: 3.81
2013-12-26 18:16:25 INFO     Measured Speed Up: 4.60
2013-12-26 18:16:25 INFO     Percentage Difference 20.9%
2013-12-26 18:16:25 ERROR    Measured speedup vs expected speedup is 20.9% and is not within 10.0% margin.
2013-12-26 18:16:25 INFO     On Demand Governor Test:
2013-12-26 18:16:25 INFO     -------------------------------------------------
2013-12-26 18:16:25 INFO     Setting governor to ondemand
2013-12-26 18:16:25 INFO     Waiting 5 seconds...
2013-12-26 18:16:30 INFO     Done.
2013-12-26 18:16:30 INFO     Running CPU load test...
2013-12-26 18:16:30 INFO     pid 4613's current affinity list: 0
2013-12-26 18:16:30 INFO     pid 4613's new affinity list: 0
2013-12-26 18:16:31 INFO     On Demand load test time: 0.24
2013-12-26 18:16:31 INFO     Percentage Difference vs. maximum frequency: 380.0%
2013-12-26 18:16:31 ERROR    On demand performance vs maximum of 380.0% is not within 10.0% margin
2013-12-26 18:16:31 INFO     Waiting 5 seconds...
2013-12-26 18:16:36 INFO     Done.
2013-12-26 18:16:36 INFO     Performance Governor Test:
2013-12-26 18:16:36 INFO     -------------------------------------------------
2013-12-26 18:16:36 INFO     Setting governor to performance
2013-12-26 18:16:36 INFO     Running CPU load test...
2013-12-26 18:16:36 INFO     pid 4613's current affinity list: 0
2013-12-26 18:16:36 INFO     pid 4613's new affinity list: 0
2013-12-26 18:16:36 INFO     Performance load test time: 0.05
2013-12-26 18:16:36 INFO     Percentage Difference vs. maximum frequency: 0.0%
2013-12-26 18:16:36 INFO     Conservative Governor Test:
2013-12-26 18:16:36 INFO     -------------------------------------------------
2013-12-26 18:16:36 INFO     Setting governor to conservative
2013-12-26 18:16:36 INFO     Waiting 10 seconds...
2013-12-26 18:16:46 INFO     Done.
2013-12-26 18:16:46 INFO     Running CPU load test...
2013-12-26 18:16:46 INFO     pid 4613's current affinity list: 0
2013-12-26 18:16:46 INFO     pid 4613's new affinity list: 0
2013-12-26 18:16:47 ERROR    Could not repeat load test times within 5.0%
2013-12-26 18:16:47 ERROR    No Conservative load test time available.
2013-12-26 18:16:47 ERROR    Not enough timing data to calculate speed differences.
2013-12-26 18:16:47 INFO     Restoring original governor to conservative