Cat 5E is the minimum one would use for Gigabit Ethernet Applications. However, Category 6 cabling is optimal because Cat 6 has additional headroom which is intended to provide quality transmission at higher rates required by today’s emerging applications. In addition, the new Category 6A cables are designed to handle up to 10 gigabits per second at frequencies up to 500 MHz.
See our Cat5e/6/6a Gigabit cables here
Additional tips and FAQs on this subject can be found here.