5 ms·
The TBW of the disk shown in the specifications is the estimated write limit of each cell multiplied by the number of cells. They don't take into account that i
by drtgh 3y ago
The TBW of the disk shown in the specifications is the estimated write limit of each cell multiplied by the number of cells. They don't take into account that in order to read the data of each cell, the adjacent cells will be written and will consume little by little these estimated write limits.
Therefore, if you fill the disk and only read data, it will sooner or later go into protection mode or lose data because of it.
They could only guarantee the TBW if more memory were added for to cover the writes consumption by the reads usage of the current 3D NAND design. I no longer know how to explain that it is programmed obsolescence, self-destructing disks by read data.
We stopped seeing 10 years guaranties when 3D NAND was introduced, so they know well what they are doing.
- fomine3 3y agoI don't think so https://www.jedec.org/standards-documents/focus/flash/solid-state-drives https://www.jedec.org/standards-documents/focus/flash/solid-...
- drtgh 3y agoWhy do you link an Industrial SSD Storage standard with write test? It only shows the cells have the corresponding write limits at beginning. My last comment, I'm sorry but I can't spend any more time with this. To read data consume writes, https://dl.acm.org/doi/10.1145/3445814.3446733 https://dl.acm.org/doi/10.1145/3445814.3446733 " Figure 1a plots the average SSD lifetime consumed by the read-only workloads across 200 days on three SSDs (the detailed parameters of these SSDs can be found from SSD-A/-B/-C in Table 1). As shown in the figure, the lifetime consumed by the read (disturbance) induced writes increases significantly as the SSD density increases. In addition, increasing the read throughput (from 17MBps to 56/68MBps) can greatly accelerate the lifetime consumption. Even more problematically, as the density increases, the SSD lifetime (plotted in Figure 1b) decreases. In addition, SSD-aware write-reduction-oriented system software is no longer sufficient for high-density 3D SSDs, to reduce lifetime consumption. This is because the SSDs entered an era where one can wear out an SSD by simply reading it." Data retention consume writes, https://ghose.cs.illinois.edu/papers/18sigmetrics_3dflash.pdf https://ghose.cs.illinois.edu/papers/18sigmetrics_3dflash.pd... " 3D NAND flash memory exhibits three new error sources that were not previously observed in planar NAND flash memory: (1) layer-to-layer process variation, a new phenomenon specific to the 3D nature of the device, where the average error rate of each 3D-stacked layer in a chip is significantly different; (2) early retention loss, a new phenomenon where the number of errors due to charge leakage increases quickly within several hours after programming; and (3) retention interference, a new phenomenon where the rate at which charge leaks from a flash cell is dependent on the data value stored in the neighboring cell. " Free way.