Choose pure copper cables – Ethernet cord manufacturers use either pure copper or copper-clad aluminum. Pure copper will give you a better connection, so look for “pure copper wire” or “TIA 568-C22” on the packaging.

However, Gigabit Ethernet still pushes the cable to its limits. Cat 6 cable is full-on certified to handle Gigabit speeds--it's meant to handle it and it does it the best.

Cat 3 and Cat 5. Both Cat 3 and Cat 5 Ethernet cables are, at this point, obsolete. You’ll still find Cat 5 cables in use, but you should avoid them altogether.