Aros/Platforms/Storage support

AROS supports hard disks and optical drives attached to several interfaces:

• #NVMe M.2 SSD (M key) on the pci-e bus
• #SATA aka Serial ATA or AHCI (IDE compatibility mode used in most cases)
• IDE (also known as ATA, #PATA or Parallel ATA)
• USB
• SCSI limited

• Controller and firmware
• DRAM better having if heavy workloads but not necessary for gaming
• Cache like SLC HMB techniques
• NAND (Main storage area with MLC, TLC or QLC versions of varying life expectancy)

SSDs, USB flash drive, SD and Micro SD Cards have a limited amount of write cycles, therefore guaranteed to fail randomly and suddenly at any time. All SSDs are prone to corrupt firmware due to poor quality NAND where both the data and the firmware resides. The drive tends to go read only when too many errors occur before complete failure.

In general, unless there is a firmware design issue, cheap materials used, stress like bending or overheating causing cold solder joints, an SSD can last a long time if minimal writing activity takes place.

General rule of thumb: the cheaper an SSD, the higher the likelihood it uses lower quality flash chips so sudden failing NAND, problematic controller chips (e.g. SandForce), outsourced firmware. Generic brand like old SP, Corsair or Crucial may be recoverable whilst major brands Samsung, Intel and Western Digital are impossible due to firmware encryption and customizations. Recommend sticking with older Silicon Motion or Phison controllers if possible.

Dram and cache are not the same thing. Dram stores the ssds indexes and metadata for faster data retrieval and wear leveling. The cache keeps part of the nand memory as SLC storage which can be written to faster. Basically all ssds will have a dynamic SLC cache where it will decrease as the drive fills up. Cache controller designs that are DRAM less use the internal SRAM cache in the controller to cache the NAND mapping table. It just requires a different mapping table design since SRAM caches are much smaller than DRAM. Ultimately the mapping table is still stored in NAND.

A ssd isn't good because it has dram or bad because it doesn't. Other things should be taken into account like sustained writes so check the TPU write intensive usage

See here for more information

Advanced Host Controller Interface (AHCI), a programming interface for SATA host controllers. Platforms supporting AHCI may take advantage of performance features such as no master/slave designation for SATA devices — each device is treated as a master — and hardware-assisted native command queuing. AHCI may but not often also provides usability enhancements such as Hot-Plug (Desktop and Mobile Only). AHCI requires appropriate software support (e.g., an AHCI driver)

AHCI, the underlying protocol for SATA, only supports one queue with 32 commands.

The issue with AHCI is that it's going to take a pile of test hardware just to figure out all the different bugs in all the motherboard chipsets and add-on PCI cards that 'kinda' implement AHCI. Not to mention Silicon Image, which took a very different approach from Intel's AHCI in their SATA controllers.

Datasheets with the SMR (overlapped packing Shingled Magnetic Recording) and CMR (faster Conventional Magnetic Recording) parts

WD:      https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/internal-drives/wd-blue-hdd/product-brief-western-digital-wd-blue-pc-hdd.pdf
Seagate: https://www.seagate.com/content/dam/seagate/migrated-assets/www-content/datasheets/pdfs/3-5-barracudaDS1900-14-2007US-en_US.pdf
Toshiba: https://storage.toshiba.com/docs/support-docs/P300-SalesSheet_English_Web_r2.pdf

NVMe accepts up to 64,000 queues with up to 64,000 commands each.