DiscounTechnology Blog

Solid state drives (SSD) are data storage devices that use either NAND flash (non-volatile) or SDRAM (volatile) memory to store persistent data. SSDs are available in 1.8", 2.5" and 3.5" form factors. Thus they emulate conventional hard disk drives and are plug compatible replacements.

Two Types of SSDs

SSDs are manufactured with either NAND flash (non-volatile) or SDRAM (volatile) memory modules.

The advantage of SSDs based on volatile SDRAM memory is their extremely fast data access - typically less than 0.01 milliseconds. This is over 200 times faster than the fastest hard drives in existence. One of their primary uses is to accelerate applications that would otherwise be bogged down by hard drive latency times.

DRAM-based SSDs volatility are also its disadvantage. Being volatile they must incorporate an internal battery and backup their data to a regular hard drive should a power failure occur. If power is lost and the battery should fail, all data would be lost.

Most SSDs are now manufacturered using non-volatile flash memory. These flash memory-based SSDs do not require batteries. This allows manufacturers to emulate standard disk drive form factors (1.8-inch, 2.5-inch, and 3.5-inch). Their nonvolatility allows flash based SSDs to retain memory even during sudden power outages. Flash based SSDs are also extremely fast compared to regular hard drives but are significantly slower than SDRAM SSDs.

The Advantages of SSDs

• Extremely low read and write latency times
• Faster startup since there is no drive spin-up time delay
• Faster random I/O compared to hard disk drives
• No moving parts resulting in higher reliability
• Lower power consumption and heat signature than hard drives

The Disadvantages of SSDs

• Cost per gigabyte is considerably higher than regular hard drives
• Slower random write speeds
• SSDs are more susceptible to magnetic fields and static charges
• Write cycles on SSDs are limited before the device wears out (100,000-5,000,000)