Weighing the Pros and Cons of SSD vs HDD

   

One of the main decisions you need to make when building a gaming computer or purchasing a pre-built system comes down to the battle in SSD vs HDD. The older technology HDD, or hard disk drive, is being replaced with SSD or solid-state disks in many system configurations.

Spinning and Reading Time Comparison With SSD vs HDD

A traditional hard drive has an actuator arm along with a read and write head to access the data, which results in the drive taking a few seconds to start or spin-up. In contrast, the SSD uses non-volatile NAND flash memory and has an instantaneous start up. The difference in the two configurations creates a significant noticeable speed difference. The RAM, or random access time, takes from 5 to 10 ms on a traditional HDD because the heads need to move and the data has to rotate under it. The SSD only takes .1 ms to access data, since it gets read from flash memory, making it up to 100 times faster than a standard HDD. The SSD vs HDD battle also ranges in power consumption. SSDs use anywhere from 1/2 to 1/3 the power needed to run a traditional HDD, which ranges from 2 watts in notebooks up to 12-18 watts in towers.

SSD vs HDD Fragmentation

Data on a HDD can become fragmented over time and use because the data gets written and erased over and over ahead, especially with larger files. Since data is read sequentially, it's necessary to defragment the drive on occasion to improve performance and speed the data read process up. SSDs do not read information sequentially and defragmenting the drive will actually write more to the NAND. This extra work decreases its lifespan.

Reliability and External Influence With SSD vs HDD

Since the HDD also has moving parts, it is subject to mechanical failure. Mechanical breakdown does not occur with the SSD because it has no moving parts. If noise is a concern, the HDD makes noise due to the moving parts while SSDs are silent. The lack of mechanical moving parts also eliminates the chance of a breakdown. If exposed to a magnet, data on the traditional HDD may alter performance and even destroy the data completely. Data access and storage are impacted by varying levels of shock, vibration and altitude changes.

Downfalls in the SSD vs HDD Battle

SSDs are not completely error-free. The primary drawback is their cost overall and on a per-gigabyte basis. Traditional hard drives cost approximately 20 to 30 cents per gigabyte and have capacities ranging from 2 to 3 TB in an affordable price range. SSDs have been released in sizes up to 2 TB, but are typically no large than 64 to 256 GB because their cost per GB hovers around $3 per gigabyte, an average of 10 times the cost of the HDD.

Encryption is also a cause for concern when comparing SSD vs HDD. The HDD can write data on the drive in any order, while NAND flash on the SSD must be rewritten on blocks that have been previously erased. It also needs secure erase procedures built into the drive for proper encryption to occur with new overwritten data.

There is also discrepancy in the difference between read and write speeds. The two are almost the same for older hard drives, while cheaper SSDs have much slower write than read speeds. The performance also greatly depends on how many free and programmable blocks are available. While the trim command can reclaim previously written blocks, having fewer programmable blocks impacts the performance of the drive.

As a consumer weighing the differences with SSD vs HDD, determine whether the benefits are worth the extra costs, which may be dropping as time goes on and their popularity increases.