[Lab] Arduino env hogging CPU?

[Justin Slootsky]

Recently, my Arduino IDE has started hogging the CPU.  (I'm running 
windows 8.1)

I was running 1.6.8, and I just tried 1.6.9 and it does the same thing.

Task Manager shows javaw.exe at about 35% (when I'm not compiling or 
doing anything), and the IDE is very laggy, barely responding to mouse 
clicks.

If I set the affinity to one or two (of my four) CPUs, then I don't lose 
control of my entire system, but the IDE is still really difficult to 
work in, and compilation takes a ridiculously long time.

When I start the IDE, there is  short period of time before the CPU 
becomes a hog.

I tried running arduino-debug to see if it showed anything, and I don't 
think so.  I see "Using proxy DIRECT" in the output.

I tried removing my line from 'Additional Boards Manager URLs', in case 
it was something there that was interfering (to no effect)

My googlefu has failed.

Any ideas?