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Comment by castratikron | Hacker News Reader

Does anyone report on eMMC wearing out in phones, game consoles, TVs, laptops, etc.? What makes Tesla special? Are there really no other car manufacturers using eMMC btw?

Easiest hardware fix would be to replace the part with a larger one which would only be a BOM change. But that doesn't help the units already in the field. I'm sure they've figured something out by now.

>Tesla’s firmware size over the years went from a paltry 300Mb to a full 1Gb over an estimated four year period, which consumes much of the storage space in that Flash. Add on the constant vehicle log updates, and the failure rate of those chips increased exponentially.

Does it really increase exponentially or does 'exponentially' just mean 'a lot' now? Genuinely curious. Also I think I'm allowed to be pedantic when the source is an electrical engineer.

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Most people replace their phones and laptops every 2 to 5 years. Too fast to see any problem under normal usage.

Most game consoles and TVs are unlikely to do enough logging to wear out their storage. But if they did, especially if they cost as much as a car, it probably would make the news.

Cars tend to last a decade or two. They shouldn't stop working because of something as silly as excessive logging.

Most game consoles have a lot more free space, use hard drives and don't do much when in sleep mode.

It’s well-known in the embedded software field that you have to be mindful about writing large amounts of data to flash storage. Yes, a lot of other products, including cars, undoubtedly use flash. This is one reason why you turn down logging to a moderate level before shipping, or store log data in a RAM disk and offload it to the cloud rather than store it locally.

> Does anyone report on eMMC wearing out in phones

Phones hit bad batteries before anything else and issues related to them get reported fairly often.

> game consoles,

I think Nintendo had a console that hit max firmware updates, instead of breaking it just meant they couldn't interfere with people rooting it anymore. There was much rejoicing.

> What makes Tesla special

An order of magnitude higher price compared to anything else you have listed. Maybe they should try to sell cars for the price of a new smart phone with the goal of selling a new one every two years so nobody would notice these long term issues.

The Nexus 7 was infamous for eMMC wear. I remember seeing several articles about it back in The Day.

> Does anyone report on eMMC wearing out in phones, game consoles, TVs, laptops, etc.?

It simply doesn't happen very much (especially not in game consoles and TVs, which don't do much writing).

> Are there really no other car manufacturers using eMMC btw?

I assume there are, but they're not writing loads of logs, or, if they are, specced their flash storage appropriately.

Assuming it writes log files at a constant rate, the rate of wear is proportional to 1/(1-f), where f is the fraction of storage taken up by firmware. Interestingly, this isn't exponential either - it's infinite at f=1!

You could argue that with f=1 there is zero sized logs and thus no wear.

(Without any static wear leveling).

> Does it really increase exponentially or does 'exponentially' just mean 'a lot' now? Genuinely curious. Also I think I'm allowed to be pedantic when the source is an electrical engineer.

I mean, exponential over what? Over time? The failure rate (more accurately the cumulative failure count) will probably grow logistically, but would have done so without the firmware size increase. Over free space reduction? That should be linear. More accurately, the amount of data you can turn over before wearing out the flash should have a linear relationship to the amount of unallocated storage available.

Maybe meaner than you, I discredit assertions from folks claiming whatever is happening exponentially as just rote repeated hyperbole...and it still annoys me.

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