Which of the following cables provides the best performance with the least EMI?

Cat 5 cables are older, unshielded or minimally shielded, and provide lower bandwidth with more susceptibility to EMI compared to newer categories.

Cat 6 cables offer better performance than Cat 5e but generally have less shielding than Cat 7, making them more susceptible to EMI in comparison.

Cat 7 cables are designed with individual shielding for each wire pair and overall cable shielding, which significantly reduces crosstalk and susceptibility to EMI, while supporting higher frequencies and data rates than Cat 5 or Cat 6. This enhanced shielding directly contributes to better performance and less interference.

Coaxial cable is a different type of network cable primarily used for older networking (e.g., RG-58 for 10BASE2) or cable television, and while shielded, it is not typically compared in the same performance category as modern twisted-pair Ethernet for high-speed data networking regarding EMI characteristics.