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Comment by Retric | Hacker News Reader

15W chips use ~2% of a HP each, and 150W = 1/5 horsepower worth of parasitic load. So using several high end chips should result in significantly worse fuel efficiency.

Are they really necessary or just cheaper in R&D terms?

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Modern cars have tons of advanced features that require a decent amount of computing. I mean just look at the evolution from radio cassette players to modern integrated GPS/media player/bluetooth/etc systems. Also things like automatic parking assist, rear view camera, computer vision algorithms to detect if the driver is falling asleep. It's feature creep all over the place.

> Also things like automatic parking assist, rear view camera, computer vision algorithms to detect if the driver is falling asleep. It's feature creep all over the place.

You have a weird definition of "feature creep". Some of those things you listed save money, others save lives. I definitely wouldn't include such things in "feature creep".

Sorry, it might not have been the right word. I didn't mean that these features weren't useful, only that in the past decades the past decades the amount of software in cars really exploded from basically 0 to having a bunch of fully featured computers dealing with various subsystems, from fuel injection to radio playback. Software "creeped" everywhere.

Optimised acceleration/deceleration would probably save more fuel than self driving hardware uses, for city driving at least.

At 60mph you'll be using 10-20hp to maintain speed so about a 1-2% loss per 150W chip(well a bit more for conversion losses).

Going by your numbers and my best guess, I think the processing of self driving cars needs 1/4 hp. The first few generations will need more than that. (you can get by on less if you are willing to sacrifice safety)

Can you break down your guess?

It takes a lot of processing to detect "objects" and figure out which are of interest. Give me a data structure of objects; with their meaning (a place that can hold the car without getting stuck) and their possible future behaviors (where it can actually get to given the laws of physics and reasonable assumptions) and a self driving car is easy. Getting that list is hard, and frankly beyond my knowledge.

Mostly I'm taking how much energy humans use, and we do a bad job...

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