It's not the size of the die (that's insane!! Imagine trying to solder that bugger in!!), rather some characteristic measurement of a transistor, or summets, on the die - but close enough, eh? (sorry I'm trying to make up for some of the piss-poor, half-arsed pedantry in this thread over the last few pages.)
Which reminds me, reading some of the whiner's comments reminded me of this:
As for day/night and weather cycles, it's fairly piss-easy to code such transitions - I'm sure they've existed since the text-based adventure games of the 80s

. It's then only slightly harder to get the visuals down.
The real challenge is properly modeling the way the cars' handling changes as a result. We're talking all sorts of things needing writing into the tyre model code, which as we all know, is the key component of any racing sim.
Look at Prologue, great suspension / kinematic model, slightly dodgy tyre model = ruined "feel" as compared with the Time Trial demo.
DragoonRaven, nice avatar