|Have a quick read of this info:|
from which you'll see that unless you're intending to run a 10Gigbit networking cat-6 is more than adequate/fine for your requirements.
So save your money and stick with cat-6.
The only places I've personally come across cat-7 is in broadcast tv environment; where it's used to distribute both digital audio and video signals/data. Although much of the general cabling was still cat-6 for office ccts.
is more on the evolution of the ethernet cable systems/standards...
What does affect a cable length performance is the number of quality of the actual cable "plugs" them selves (how well they are made and secure); the number of breaks/connections in the run... Each connector (an in-line coupler) represents a drop in signal quality. Some regard each such in-line connector as equivalent to 40ft of cable... But I have no firm evidence to support that actual figure. It is generally not recommended to have more than 5 connections in a given run - which includes the cable end connections themselves... So one's options for extending with more than one (possibly two) couplers is somewhat limited... Which is why if needing a long run best to aim for a single run - or at worst - two suitable longish runs (to provide again upto a max overall of 100meter/328ft) with a quality in-line coupler. Or use a suitable hub/switch etc. to extend as that will "boost" the signal for a further 100meters/328ft.
message edited by trvlr