If your sig is really your hardware, I have a hard time believing you dunno what 1T is.
1T typically means about 1k more mb/s bandwith in memory benchmarks, and about 5% performance increase in applications.
Launching regular, day to day apps like Firefox-- or whatever-- at 1T they will start up a little bit snappier than at 2T, but if you didn't know about 1T/2T you'd never notice the difference.