SSD SURVIVAL

Solid State Drives have been around for a long time. NASA uses flash storage for spacecraft as it can tolerate the radiation and vibration that would trash a hard disk.

The first generation of SSD for computers used a single cell per bit. Lower cost multiple cell devices expanded the market. Most recently large scale stacked flash memory called V NAND have reduced prices and increased capacity

SSD cells tend to wear out and servers often wore out early drives in a few years. Work to improve the durability has been very successful.

Using wear leveling algorithms and over provisioning the cells has allowed SSD drives to become durable enough for long term active storage. Testing SSD writes have discovered that SSD can last a very long time. Consumers do not generally write vast amounts of data to their SSD. Write amplification occurs when a small 4K block is rewritten repeatedly which can use multiple blocks over time..Large capacity SSDs manage wear leveling more easily with vast amounts of free space.

LAPTOP SSD

Laptop computers often shipped with low capacity low speed hard disks that throttled performance considerably. SSD products are made to fit the hard disk bay and these products have been well received by consumers. Over time the capacity and quality of the SSD has improved considerably.

Early SSD drives managed 230MB/s read and 210MB/s write while more recent drives now saturate SATA III speeds with 550MB/s read and 520MB/s write..

TRIM

The SSD TRIM command was added early on. TRIM informs the SSD that certain blocks are not in use anymore. This allows the SSD to erase the blocks for use. Windows 7 supports TRIM for SATA SSD only. Windows 8 and above support NVMe which supports other classes of SSD.