Write limit? Is there one?

[blackbolt22]

How many write entires or write calibrations can be done before the PCM degrades.

I'm assuming R&D vehicles get countless writes and have no issues?

100
1000
10000?

Not exactly on topic, why does a write cal still take a minute or so if say only one value is changed? Is the entire calibration area being written each time? Why couldn't that one value be changed?

[Ruiner46]

Modern flash memory can typically handle around 100,000 erase cycles. It depends on which type of memory they use, but the short answer is at least thousands, if not 100,000.

[Montecarlodrag]

Flash memory used on old 99-02 LS1 PCMs is rated to 100,000 program/erase cycles. This means, if you erase and program a PCM 10 times a day it would take 27 years to wear the flash chip. Modern chips have 1 million cycles.
Flash memory does not allow to write single bytes in a random fashion, if a bit is set to 0 only a erase can set it to 1 and the entire block has to be erased, it isn't possible to erase only 1 bit.

To write only the changes to a flash chip the programmer has to first do a compare operation which means it has to read the whole chip to compare it against the loaded file. The software can't know what the contents are without a full read. This takes longer than just flash the whole calibration at once.

I have seen software that allows you to load the previous file and the current one, compares them then erases and writes only the memory blocks that have changes. It speeds the flashing a lot but you need to be very careful with file management, it's possible to brick a PCM if you make a mistake. However this is not really needed on 99+ PCMs

Realistically You won't flash a PCM that many times to damage the chip, you will die of boredom if you try.

[blackbolt22]

Flash memory used on old 99-02 LS1 PCMs is rated to 100,000 program/erase cycles. This means, if you erase and program a PCM 10 times a day it would take 27 years to wear the flash chip. Modern chips have 1 million cycles.
Flash memory does not allow to write single bytes in a random fashion, if a bit is set to 0 only a erase can set it to 1 and the entire block has to be erased, it isn't possible to erase only 1 bit.

To write only the changes to a flash chip the programmer has to first do a compare operation which means it has to read the whole chip to compare it against the loaded file. The software can't know what the contents are without a full read. This takes longer than just flash the whole calibration at once.

I have seen software that allows you to load the previous file and the current one, compares them then erases and writes only the memory blocks that have changes. It speeds the flashing a lot but you need to be very careful with file management, it's possible to brick a PCM if you make a mistake. However this is not really needed on 99+ PCMs

Realistically You won't flash a PCM that many times to damage the chip, you will die of boredom if you try.

Thanks for the detailed explanation! Excellent!