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Comment by phkahler | Hacker News Reader

OK. I've worked on several EVs with 100kW motors. Lets do some math. A really good EV takes around 200 to 250 watt-hours per mile. On the EPA urban drive cycle you average just under 20 miles per hour. If you have 100 miles range, that will take around 5 hours in urban driving. A 40 watt load for 5 hours is 200 watt-hours. Your Intel processor running near 100 watts is going to cost you 2.5 percent of the range. Or if you look at costs, it's going to take that percentage of the battery cost to run it.

Sure an EV can suck 100kW or more of power, but only for a short time. And it can be put back into the battery via regenerative baking. Range is incredibly sensitive to electrical loads.

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The power used by a processor is mostly a matter of performance rather than ISA. You might be able to make a non-x86 processor with similar performance that only takes 95 rather than 100 Watts but that's the extent of it.

The reason that ARM processors are able to take so much less power than Intel is because their single threaded performance is much lower. As single threaded performance increases linearly the power required goes up as the square of that for architectural improvements and as the cube for frequency improvements modulo FO4 delays.

Intel's Atom processors haven't gotten huge amounts of love from the parent company but for DSPish code of the sort that cars are mostly running they should perform comparably to the equivalent ARM options.

You're stuck in the mindset that the consumer CPUs that you can purchase are the only ones Intel can make. They can and do make custom chips, extremely custom, for large customers and government agencies. It would be very, very easy for them to mass produce a chip that drops all the unnecessary features for an "appliance" like self-driving cars.

Let's look at it a different way. The MacBook battery is 55 watt-hours, the Tesla battery is 100 thousand watt hours. They both run their respective workloads for a similar amount of time. So, less than a tenth of a percent?

Don't confuse watts with watt-hours. My math stands.

Why would you assume they'd be using a CPU running at 100W???

I can get an off-the-shelf Xeon-D 8-core processor that runs at 35W and any single core would STOMP every ARM chip on the market. If I were to build that chip specifically for a car platform my power envelope would drop accordingly.

https://ark.intel.com/products/family/87041/Intel-Xeon-Proce...

This is an embedded application... not a gaming computer. If I move to Atom - which is what would likely be used for this sort of thing, you're talking less than 5W.

https://en.wikipedia.org/wiki/List_of_Intel_Atom_microproces...

>> This is an embedded application... not a gaming computer. If I move to Atom - which is what would likely be used for this sort of thing, you're talking less than 5W.

Correct. But Atom processors performance are no better than the competition and don't currently have any of the common automotive peripherals (CAN for example).

Intel is the device manufacturer... it doesn't matter if they're "better". They get to choose what they put into their own hardware, this isn't an open audition.

Regardless, you're missing the point. Intel has the means to get into the space and create appropriate CPUs to compete. This acquisition makes it clear they're planning on doing just that.

I didn't - I just dropped the time factor out (since they both run their workloads for similar lengths of time).

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