7.68 TB on a single stick: the SanDisk SSD built to outlive your NAS

The SanDisk NAS 600 SATA is offered as a caching device in storage built on hard disks, though it can also serve as the main drive. The form factor is 2.5 inches at 7 mm thick, connected over SATA at 6 Gbit/s.

Capacities are 500 GB, 1, 2 and 4 TB. Sequential read reaches 560 MB/s and write 520 MB/s, with up to 87,000 random read IOPS and 77,000 random write IOPS. The 4 TB version is rated up to 2500 TBW with mean time between failures up to 2.25 million hours. All versions carry a five-year warranty.

The SanDisk NAS 800 NVMe SSD in the M.2 2280 format targets all-flash storage under high load. It uses TLC 3D NAND over a PCIe 5.0 interface, in 960 GB, 1.92, 3.84 and 7.68 TB capacities.

The 1.92 TB version delivers up to 14,900 MB/s sequential read and up to 13,200 MB/s write. The top 7.68 TB model is rated at 14,000 TBW. The warranty is five years as well.

Both drives go on sale in the Indian market in September. The manufacturer quoted prices in dollars.

• NAS 600 SATA: 500 GB — $224, 1 TB — $349, 2 TB — $624, 4 TB — $1249.
• NAS 800 NVMe: 960 GB — $387, 1.92 TB — $699, 3.84 TB — $1374, 7.68 TB — $2749.

Speed on the spec sheet is the most visible figure and the least useful one when picking a NAS drive. A 1 Gbit/s network delivers about 110 MB/s and a 10 Gbit/s one about 1.1 GB/s, and that is where everything stops, not at the drive. Two other numbers keep mattering.

• Write endurance. 2500 TBW at 100 GB written per day is roughly 68 years; at 1 TB per day it is about seven. Calculate from your own profile rather than from a marketing promise.
• The drive's role. A cache survives many times more rewrites than an archive drive: pick endurance for cache, capacity for archive.
• Thermals. A PCIe 5.0 NVMe drive in a cramped NAS chassis heats up, and without a heatsink and airflow the speed drops to SATA levels on its own.
• Compatibility and the NAS vendor's support list: not every chassis delivers full M.2 speed and not every one provides cooling.

A dedicated NAS line is useful because the manufacturer finally states endurance and duty cycle rather than speed alone. For home storage the network and the capacity matter most; for working storage it is write endurance and cooling, and those are the numbers worth comparing between models.