<p>The synthetic drivers ‘talk’ more directly to the actual hardware, bypassing most of the hypervisor (for common data operations). This dramatically cuts down on the hypervisor overhead related to most network activity.</p>
<p>If your server doesn’t communicate much on the network, or if your hardware is well undercommitted, you should be fine with the emulated drivers. There’s definitely a performance penalty for doing this cependant.</p>