Re: En analysant la question sous l'angle des cas d'utilisations

OK, maintenant je pense savoir et comprendre pourquoi Kingston vend des SDcard "TLC in pSLC mode", ce qui me semblait a priori choquant, vendre de la TLC pour de la "qualité industrielle" revendiquée.

Pour les différent support typee NAND (eMMC, SSD, SDcard), "TLC in pSLC mode" est un moyen de d'augmenter la durabilité, et aussi par effet secondaire les débits, pour les mémoire flash fabriquées en TLC, et apparemment les QLC aussi.
( https://www.atpinc.com/en/blog/3d-tlc-pslc-with-mlc-slc-endurance )

Pour cela, simplement, on utilise un seul bit dans la cellule multi-bit, et donc on élimine les inconvénients des MLC.

On troque donc de la capacité contre de la durabilité.
Il est dit qu'on multiplie la durabilité des TLC par un facteur 10.
( Pseudo SLC (pSLC) https://www.udinfo-tech.com/technology/data-erase-5/ )

Comme les TLC/QLC sont bon marché, c'est un compromis.

Cela permet d'obtenir des durabilité de SLC avec des TLC.

C'est bien le cas d'usage dont je parlais, à savoir un pc auquel l'accès est limité ou coûteux, comme un équipement IoT.

What use cases is pseudo-SLC aimed at?
While most contemporary enterprise use cases are well-suited to MLC, TLC and SLC flash storage, there are some edge cases where SLC is desirable.
These can literally be edge computing workloads, where the extra durability is required. Think cases where compute and storage is sited in a remote location where physical maintenance visits may come few and far between, such as internet of things (IoT) applications and military, oil and gas.
Elsewhere, but less often, SLC-type performance may be the requirement, such as for high-end transactional workloads in the enterprise where some pseudo-SLC can help.

(Pseudo-SLC flash storage: What is it, what’s it good for and what does it cost? https://www.computerweekly.com/feature/Pseudo-SLC-flash-storage-What-is-it-whats-it-good-for-and-what-does-it-cost )

• SDcards :

Delkin Devices microSD/microSDHC Industrial SLC SD
https://www.delkin.com/products/industrial-microsd/industrial-slc-microsd/

Delkin Industrial microSD
https://www.delkin.com/products/industrial-microsd/

Delkin microSD Cards, the Industrial Applications Market, and One-of-a-Kind Storage Solutions for Rugged Environments
https://www.delkin.com/blog/microsd-cards-the-industrial-applications-market-and-one-of-a-kind-storage-solutions-for-rugged-environments/

• Sources intéressantes :

Delkin Understanding PseudoSLC (pSLC)
https://www.delkin.com/blog/understanding-pslc/

SLC, pSLC, MLC and TLC Differences - Does Your Flash Storage SSD Make the Grade?
https://www.cactus-tech.com/resources/blog/details/slc-pslc-mlc-and-tlc-differences-does-your-flash-storage-ssd-make-the-grade/

4 reasons to use industrial 3D TLC NAND flash as pseudo-SLC
https://www.swissbit.com/en/blog/post/4-reasons-to-use-industrial-3d-tlc-nand-flash-as-pseudo-slc/

Unlocking NAND Flash technology – SLC, MLC, TLC, and pSLC
https://www.szyunze.com/support/unlocking-nand-flash-technology-slc-mlc-tlc-and-pslc/

KIOXIA America Inc.
https://americas.kioxia.com/en-us/business/memory.html

Understanding pSLC SSDs: The Perfect Balance of Performance, Endurance, and Cost
https://www.ssstc.com/knowledge-detail/understanding-pslc-ssd-performance-endurance-cost/

• PDF : https://www.techpowerup.com/forums/attachments/micron_1100_ssd-pdf.310943/

https://americas.kioxia.com/content/dam/kioxia/en-us/business/memory/mlc-nand/asset/KIOXIA_pSLC_for_IoT_Devices_Tech_Brief.pdf

https://media.kingston.com/pdfs/emmc/firmware-config_us.pdf

• Tableau comparatif

NAND Flash Type	Feature	P/E Cycle	W/R Speed	Price
2D NAND	SLC	Single-Level Cell	60,000-100,000	Best	Expensive
2D NAND	pSLC	Pseudo SLC	20,000-50,000	Great	Between SLC & MLC
2D NAND	MLC	Multi-Level Cell	3,000	Good	Cheap
3D NAND	3D pSLC	3D Pseudo SLC	20,000-50,000	Great	Close to MLC
3D NAND	3D pMLC	3D Pseudo MLC	3,000	Good	Between 3D pSLC & 3D TLC
3D NAND	3D TLC	3D Triple-Level Cell	1,000-3,000	Worst	Lowest

• Schéma

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