The GeForce 700 series came in 3 different microarchitectures. Most were on Kepler but there were several fermi (the previous uarch) and a few mobile chips used maxwell (the following architecture).

Lest anyone think AMD is any better the Radeon 200 series came in everything from terascale 2 (4 years old at that point) to GCN3.

The gpu manufacturers have also engaged in incredible amounts of rebadging to pad their ranges, some cores first released on the GeForce 8000 series got rebadged all the way until the 300 series.