Ignoring the use of fiber here, the IEEE 802.3ab defines Gigabit Ethernet over UTP at 1000Base-T over 100 meters. But, this standard was created around the use of CAT-5 cabling. As tech has progressed, it became easily possible to achieve faster data transfer rates with what is still considered “Gigabit Capable” ports and cables. Just because something is rated as Gigabit, does not in any way mean that is the max it is capable of. MystiCom was able to use CAT-5 for 10Gb/s transfer back in 2002. Notwithstanding that you completely omitted any other hardware capabilities/limitations such as backplanes or line cards, you simply saying “you can’t” and that gigabit ports “cap out around 940mbps” is simply incorrect. What you seem to be referring to are the data rates that ISP’s offer in their brochures where they throw up an asterisk and say that over head may reduce their gigabit plan to 940mbps max. So yes, while the above is not incredibly in-depth, you way oversimplified what gigabit entails and what impacts that performance. And telling someone that “anything reported over that is a bad measurement or a bug” is just incorrect information.

Good one. Couldn’t have lived without this input….

This is a gross oversimplification and, resultantly, an overall false statement.