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Comment by dannyw | Hacker News Reader

Hopefully the cost of this recall exceeds the cost savings of Tesla choosing eMMC.

eMMC is fine if used appropriately. The problem appears to be that Tesla is (or was) writing frequent log file updates to eMMC, resulting in huge write amplification and a quick exhaustion of wear cycles.

What’s the alternative to using an eMMC? Straight up SSD?

Enterprise grade SD card in a location that can be replaced.

If you buy in enough bulk, demand the emmc provider give you the source code and firmware update procedure for the emmc card. Get them to sign over rights to use that code to update cards you have purchased in the field.

There is no such thing as a failed emmc card - it's simply that the built in firmware has failed to correctly remap data around failing flash sectors. There is always life left in the actual flash provided you're happy to throw enough error correction at it.

Tesla’s volume isn’t even close. A million cars is a lot of cars, but we’re talking about smartphone hardware. A million phones is not a lot of phones.

The right solution is to use higher quality storage and to keep frequently-written logs on a removable device.

This is true. Early SSDs had double digit failure rates because of buggy controllers. The situation has gotten better but if you stress out cheap eMMC in an embedded application like a car there is a decent chance that the controller fails.

SPI NOR flash

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