Synergy is a great and free way to replace a KVM switch (kind of). It doesn't do video, but it does keyboard and mouse control across multiple networked workstations awesomely.
I was having issues with high CPU utilization on Mac OS X with Synergy. I am using Ubuntu 11.04 as the Synergy server and Mac OS X as the client.
The Synergy project has gone through some changes over the last year or so. It was forked a while back to a new project called Synergy-Plus. But now things have come back together and the projects have merged to be one again. This is generally a good thing and one of the reasons why open source is so great.
A fork is sometimes subversive (heck maybe all the time), but it also allows the project and the technology to continue to grow and mature, even if the original project isn't on board with the changes. In the best case scenario, everyone can literally patch up their differences and merge a fork of a project back with the original and keep the ball rolling full steam ahead.
I had a mix of older Synergy Plus versions going between Ubuntu and OS X. I was noticing a huge load on my Mac CPU just by moving my mouse around in circles.
Synergy is normally a very low overhead app. This was not normal at all. So I upgraded all of my workstations to the latest version (1.44 beta). It is not available in the Ubuntu repos so I had to download and install the .deb manually.
Once I got everything on the same and newest version, OS X zips along like usual. Synergy is one of my most favorite applications. I use it every day at work, and frankly could not do my job without it. Go check it out!
Update:
I ran into a weird problem with 1.4.4. Double-clicking on Mac OS X stopped working. So I dropped back to version 1.3.5 which is referenced in the bug report and both my CPU and my double-clicking are happy now :).
