Is flash drive zeroed or translator wiped ..
Posted: Wed Dec 06, 2023 2:32 pm
I had this idea we might be able to detect somehow without chip-off to see reading back zeros or FF pattern may be due to a pattern written or wiped translator.
Hypothesis being: I expect wiped translator to result in faster read-speed than reading back a pattern that was written and possibly power consumption of reading from wiped translator < consumption of reading an actually written pattern. If we look at voltage needed for various flash operation we see order of read, write, erase. But even for read a charge pump needs to up voltage by a bit and so it may give measurable increase in power consumption. This is my somewhat layman understanding, feel free to correct me (@fzabkar). If we consider wiped FTL the controller may not even need read the NAND.
In advance I need to say I need to repeat this test with a faster UFD. This is an ancient UFD, USB 2, so USB bandwidth may be troubling results of read back speeds.
I don't see difference in read back speeds, though the flatter line in case of wiped FTL may be worth investigating:
Difference in power consumption is small but measurable ..
Reading back from zeroed drive:
Reading back from drive with FTL wiped:
I will follow up when I have more tests with USB 3.x UFD. Perhaps I should get a measure apparatus that can save data so I can plot stuff.
Hypothesis being: I expect wiped translator to result in faster read-speed than reading back a pattern that was written and possibly power consumption of reading from wiped translator < consumption of reading an actually written pattern. If we look at voltage needed for various flash operation we see order of read, write, erase. But even for read a charge pump needs to up voltage by a bit and so it may give measurable increase in power consumption. This is my somewhat layman understanding, feel free to correct me (@fzabkar). If we consider wiped FTL the controller may not even need read the NAND.
In advance I need to say I need to repeat this test with a faster UFD. This is an ancient UFD, USB 2, so USB bandwidth may be troubling results of read back speeds.
I don't see difference in read back speeds, though the flatter line in case of wiped FTL may be worth investigating:
Difference in power consumption is small but measurable ..
Reading back from zeroed drive:
Reading back from drive with FTL wiped:
I will follow up when I have more tests with USB 3.x UFD. Perhaps I should get a measure apparatus that can save data so I can plot stuff.