The SSD vs HDD debate continues to rage on even though the advantages of solid state drives (SSDs) are becoming more apparent. If you’ve ever experienced a head crash, stiction, or painfully slow read/write speeds, then you know first hand the frustrations that accompany hard disk drives (HDDs). Due to the mechanical build of HDDs, the possibility of hardware issues and limitations on performance are inevitable.
SSDs may be expensive, but they are well worth the price when you consider their advantages.
So what if disks didn’t spin and could create rewritable storage without the need for platters, spindles or heads? This is where the cracks in the ceiling of SSD vs HDD are exposed. Built without moving parts, the advantages of SSDs have made them a popular choice for server vendors, SAN vendors and appliance manufacturers. Why? Not because they’re cheap – they’re not. But they’re well worth the price when you consider the advantages. Here are 10 reasons you should choose SSDs over HDDs.
SSD vs HDD: Top Ten Advantages
1. Longer Lifespan
Mechanical drives have an average lifespan of three to five years. Many fail long before the lower end of the average, and few last beyond the upper end. At three years, you should seriously consider a refresh. At five years, you’re skating on ice so thin it’s really just very cold water. Alternatively, SSDs have life expectancies reaching into decades, although trusting the 1 million to 2 million hour SSD expectancy claims seems as ridiculous as the 500,000-hour claims of mechanical drive manufacturers. Expect your SSDs to last two to three times longer than mechanical drives.
2. Faster Read and Write Speed
Since SSDs have no moving parts, their read and write speeds are impressive compared to their mechanical counterparts. Depending on the form factor, read/write performance between SSDs can vary. But to get a baseline for an SSD vs HDD speed comparison, a standard SSD can read sequential data at around 550 megabytes per second (MBps) and write data at 520 MBps. New NVMe SSDs even have the ability to reach speeds of 3,000 MBps or more. On the other hand, even a higher-end HDD may only reach a speed of 160 MBps.
3. Form Factor
SSDs come in a variety of form factors, offering far more flexibility when designing a system. Some are made to act as a replacement for HDDs, which come in sizes of from 1.8″ to 5.25″, and use the same SATA connector. Because data on SSDs is stored on interconnected integrated circuit chips rather than mechanical disks, reducing their size can be taken a few steps further. With rack space at a premium, that’s a very good thing.
The next size down uses mini-SATA (mSATA) connectors which can also be installed in a PCY Express expansion slot. The smallest and by far best performing SSDs have a form factor known as M.2 that uses the NVMe interface. These SSDs are mounted directly on the motherboard which frees up a sizable amount of space for other components or simply more storage. These are the most expensive option but offer the biggest benefits.
4. Shock Resistance
SSDs are a good choice for mobile systems due to their shock resistance from drops, bumps and g-forces. Such forces don’t often act on standard concrete and steel data centers, but what about mobile ones – mobile data centers such as those used by ground military forces, aboard ships, on aircraft or at trade shows? Movement can have devastating effects on mechanical drives, especially during write events. SSDs, again having no moving parts, aren’t affected by mobility and are well-suited to such physical abuse. SSDs can withstand up to 1,500 g during operation or 25 times that of a standard drive.
5. Failure Rate
Any mechanical or electrical device can, and will, fail but the failure rate is much higher when the parts are in motion. Mechanical disks are not particularly robust and can fail at any time, as one manufacturer’s representative once stated, “Any time between 15 seconds and 10 years.” While SSDs haven’t quite reached the adoption level of mechanical drives, manufacturers estimate very low failure rates compared to standard technology.
6. Power Loss Protection
Enterprise-class SSDs rely on power failure circuitry to monitor voltage changes as a form of power loss protection. If the voltage drops below the threshold, a secondary voltage hold-up circuit ensures that the drive has sufficient power to save any pending writes. A supercapacitor, a discrete bank of capacitors or a battery acts as this secondary voltage hold-up circuit.
7. Power Consumption
Power consumption from SSDs is considerably less than mechanical disks. Even at a full sprint, SSDs consume approximately three Watts or less compared to six or more Watts by standard disks. When idle, SSDs sip from 0.05 Watts to 1.3 Watts, while their gluttonous counterparts gobble at a rate of 4 Watts or more. And because SSDs can access data much faster than disks, they will remain idle more often. You will pay more for an SSD upfront, but the long-term cost reduction in power might offset the initial sticker shock.
8. Heat Dissipation
Everyone knows heat kills electronic performance, which makes reduced heat dissipation a valuable asset. SSDs reduce heat dissipation significantly compared to their spinning cousins. Less heat to move away from sensitive electronics means lower cooling requirements and less power consumption, which in turn means reduced costs for data centers. Mechanical drives are responsible for more than 70 percent of the heat generated from a system. Without them, you could realize sizable savings and longer-lasting hardware.
9. Hot Plug and Unplug Capability
It might not surprise you to know that SSDs have hot plug and unplug capability. However, you may be surprised to find out that because SSDs don’t have to “spin up,” their capacity is available immediately upon plug-in. Although it might take several seconds for your operating system to recognize the drive, you will not have to wait through a lengthy discovery process or an even lengthier reboot.
10. Noise Level
If you’ve ever stood in a data center, you probably noticed the very high noise level. Imagine a data center filled with SSDs instead of standard drives. Other than the sound of system fans, cabinet fans and the central air conditioning system, the data center becomes significantly quieter. However, fans would also likely experience a ‘downsizing,’ further reducing the ambient noise level.
Ken Hess is a freelance writer who writes on a variety of open source topics including Linux, databases, and virtualization. He is also the co-author of Practical Virtualization Solutions, which was published in October 2009. You may reach him through his website.