If you do your networking through a supported network interface card (NIC) rather than via PPP, you’ll find that most everything works exactly as it should. However, there are many hardware-related things you can do to make sure your network connection is fully optimized, including using the right cable type, taking care when mixing 10 and 100Mbps components, and ensuring that full-duplex NICs aren’t talking to half-duplex hubs.
Be’s Hank Sackett has prepared an excellent overview of factors that can limit network performance. Read it here.