Results from the test here.
So as I continuously run background apps and monitors, naturally I have to sacrifice burning some CPU cycles. But frankly, I think that its akonadi and nepomuk file indexer that are using much of it. Then there's conky and superkarmaba making calls every second or so.
Any advice? Thanks.
The report from runlevel 3 look fine, this exclude hardware and drivers related loads, in fact the it show a CPU usage very low.
The second report, system running X but no apps, look a bit high, by comparison that's mine (using a custom kernel... and nvidia 295.49 driver):
# sar 15 3
Linux 3.2.16-pclos7.pae.preempt (dv1710.as) 05/07/2012 _i686_ (2 CPU)
11:32:29 AM CPU %user %nice %system %iowait %steal %idle
11:32:44 AM all 0.03 0.00 0.10 0.07 0.00 99.80
11:32:59 AM all 0.07 0.00 0.14 0.00 0.00 99.80
11:33:14 AM all 0.07 0.00 0.14 0.00 0.00 99.80
Average: all 0.06 0.00 0.12 0.02 0.00 99.80
One thing to notice is that I'm running a non bfs kernel,
which is clocked at 100 Hz instead of 1000 Hz, I would be interested to know your results using a non BFS kernel, from my trials the frequency change lead to different results.
In fact I'm actually evaluating to provide a 300 Hz kernel (not available at the moment), which could be a trade off between the 100 and 1000 Hz.
You can run
top or
htop to look at which process is really CPU hungry.

Finally the report while running all apps, show a noticeable amount of time spent waiting for I/O, ( approx 6% ), of course that doesn't eat CPU cycles, therefore the effective CPU usage is around 19% which is certainly an high amount for a system considered idle. I would try to start one app at a time, trying to identify the most CPU hungry.

AS