Does adding an adapter to "convert" ports slow down the transfer rate?

Question

I want to add an eSATA port and am looking at Internal SATA to eSATA II External and PCI controller to eSATA. Are these solutions slower than if the motherboard has eSATA (or any other port for that matter) built-in?

Answer 1

An adapter will slow down the connection insignificantly and isn't worth the trouble of buying a new motherboard.