- Allows clipboard copying
- Allows for more than two computers
- Don’t need to press any buttons, each time you want to switch from one PC to another
- Any networking event that changes the server’s IP address requires all clients to manually have to update their settings
- Spotty connections, especially over Wi-Fi can cause jittery mouse movements and connectivity issues.
- No reliance on a network means there are never any connectivity issues.
- Can switch over more than just a keyboard + mouse — you can switch over webcams, microphones, etc.
- Need to press a physical button, and wait for a second for the USB devices to activate — on every switch between PCs
- Once Synergy is set up once, so long as there's no IP address change, the time/context-switching involved is much higher with a KVM switch.
- No clipboard sharing.
Overall, if you are rarely resetting your internet router, or switching from wifi to ethernet often, it’s unlikely your IP address will be changed, making Synergy the better option.
If your internet connectivity is not the best, and you need smooth mouse movements (gaming, graphics editing) then a KVM switch would be ideal.
I use both!