It's really not.
They ran out of compute on one node in mid-2020 and have had to spill over to use the second node ever since. See the full thread here for where Green mentions this has been the case since then and not getting better.
And that's a system VASTLY less capable than the L4 system promised to pre 3/19 buyers.
So the idea they'll somehow magically add a ton of functionality that currently does not exist at all and ALSO reduce required compute by at least 50% to fit back in a single node (since you need redundancy as per AI day presentation to run without a human in the car) is magical thinking unsupported by any evidence.
<citation required>
And ideally a citation that has more substance than "they'll somehow just make everything way more efficient *waves hands*"
Again,
nobody knows how much compute is actually needed for L4 driving on a Tesla. Not Elon, and certainly not James Douma who AFAIK has even
less visibility to Tesla code than Green does....and that will be true of everyone until they
actually achieve it. Which they have not.
Douma is the guy who told us how they didn't need LIDAR but that RADAR was
super useful to FSD and it totally made sense they used it.... right up until Tesla announced they're removing radar... at which point he did a Dave Lee video telling us how no, just kidding, Radar wasn't
really super useful at all and it totally makes sense to remove it.
But we do know they're WAY past using all the compute available in a single HW3 node, even at L2, and have been for roughly 3 years now.
In fact, hilariously, Douma is one of the original sources for HW3 having run out of compute years ago: