Earlier quoted context omitted.
Good point on power dissipation and efficiency-- a T480 might not be substantially faster than a T430, but it's half the size and the battery lasts longer.
They're much faster. 50-60% on the single core stuff and 300% faster on multi-core tests. Not to mention they cruise along on things that use the newer extensions for things like video playback, plus the integrated graphics hardware is much much faster
[citation needed] 50-60% is absurdly large for single core, the reality is 20%, and 300% is crazy. The T480 uses a 15W quad core on the same 14nm process as the 15W chip in the T470 and because it's slightly more power efficient there's a little gain, about 25-30%. So the difference between the Sandy Bridge T420 to Kaby Lake Refresh T480 is perhaps 50% in multi core.
Here's my favorite Sandy Bridge to Kaby Lake IPC benchmark collection: https://www.hardocp.com/article/2017/01/13/kaby_lake_7700k_v...