Dropbox causes high CPU usage on Mac OS X 10.8.2 (Mountain Lion)

Taken from this Ask Ubuntu question:

Dropbox computes a hash of all files that it's going to sync, it uses it both to determine if they changed and to avoid uploading content that is already in their cloud (another customer has the same file). Calculating hashes takes CPU power. It's usually noticeable at login.

So it seems that the only way to fix it, will be to reduce the size of your shared Dropbox folder.

I have found solution here: http://www.michaelcarwile.com/throttle-dropbox-and-other-app-cpu-usage/

Install cpulimit:

brew install cpulimit   

Get Dropbox’s Process ID:

ps aux | grep Dropbox

user 19628 104.7 2.3 xxxxxxxx xxxxxxxx ?? R 4:07PM 15:47.12 /Applications/Dropbox.app/Contents/MacOS/Dropbox

Run cpulimit with the -p flag using the process ID:

cpulimit -p 19628 -l 40

Note: That’s a lowercase L (for limit) and the last number (40 in this case) is the percentage % of CPU you’d like to throttle the app to.

Also Note: cpulimit will output ‘Process xxx found’ and will continue to run until you kill it with + C