Standard HDD drives contain multiple disks called platters, which are covered in a magnetic coating and then rotated at high speed. Drive heads then move across the platters, changing the magnetization of the material beneath to record data, or reading its state to return the stored information.
While the core HDD ideas are simple enough, allowing manufacturers to produce high capacity drives at very low prices, they do pose several problems.
Both reading and writing data requires a lot of work, for instance. Heads must move around, and the platter must spin to exactly the right point before the drive can do anything. This all takes time, and is why hard drives are one of the major performance bottlenecks in many PCs.
Having to move all these components around also means there’s a constant power drain, an issue with laptops and netbooks.
And the drive heads gets incredibly close to the platter – a tiny fraction of the thickness of a human hair – so if there’s a shock at the wrong time then the two may collide, damaging the drive and losing data. Drive manufacturers employ a range of technologies to prevent this from happening, and as a result these head crashes are rare, but they can’t be ruled out entirely – there’s always some risk.
You don’t have to live with these issues, though: SSD technology can address them all, though at a significant price.
SSDs have several advantages over traditional mechanical (spinning) disks, and when you look at the two technologies, then, it’s clear that solid state hard drives are technically superior in many areas. Here are 10 of the most frequently quoted advantages of SSDs over mechanical disks.
Since SSDs have no moving parts, their access and seek times are many times faster than those of their mechanical counterparts. Their performance is impressive and it’s truly a joy to use. They’ve a write speed that’s generally above 200 MB/s (In some devices they reach the level of 500 MB/s) and up to 500 MB/s for cutting edge drives.
2. Life Expectancy
Mechanical drives have an average life expectancy of three to five years. Many fail long before the lower end of the average, and few last beyond the upper end of the average. 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.
3. Failure Rate
Any mechanical or electrical device can, and will, fail, but your chances are greater for failure when those 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 reached the adoption level of mechanical drives, manufacturers estimate very low failure rates compared to standard technology.
4. Hot Plug/Unplug Ability
It might not surprise you to know that SSDs have hot plug and unplug capability. However, it might surprise you to know that since 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.
5. Power Consumption
SSDs draw very little power. Even at a full sprint, SSDs consume approximately three Watts or less compared to six or more Watts by standard disks. However, most impressive is the power consumption of quiescent drives. SSDs sip from 0.05 Watts to 1.3 Watts, while their gluttonous counterparts gobble at a rate of 4 Watts or more. You will pay more for an SSD, but the long-term cost reduction might offset the initial sticker shock.
6. Physical Size
You usually see standard disks in 3.5 inch or 2.5 inch formats, but SSDs take small form factor two steps further with 1.0 inch and 1.8 inch disks. These smaller sizes allow manufacturers to build smaller appliances, mobile systems and blades that occupy very little space. With rack space at a premium, that’s a very good thing.
7. Heat Dissipation
Everyone knows heat kills electronic performance. That’s why data centers have to stay at those chilly temperatures. SSDs reduce heat dissipation significantly compared to their spinning cousins. Less heat loss means lower cooling requirements, which in turn means reduced costs. Less heat to move away from sensitive electronics also means that system fan sizes can shrink along with your power consumption. 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.
8. Shock Resistance
SSDs are a good choice for mobile systems due to their resistance to 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.
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. As noted in the Heat Dissipation entry, fans would likely experience a ‘downsizing’ as well and further reduce the ambient noise level.
10. Power Loss Protection
Enterprise-class SSDs rely on power failure circuitry to monitor voltage changes. 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 to disk. A super-capacitor, a discrete bank of capacitors or a battery acts as this secondary voltage hold-up circuit.
If you’re looking to optimize an existing desktop, then an SSD can be very useful. You’ll then benefit from faster boot times, and a general speed boost as Windows components are loaded more quickly.
And of course SSDs can be particularly welcome in laptops, although this does depend on what you intend to do with them.
If you’re planning to buy a laptop as a desktop replacement system, something that will run lots of applications, then an SSD probably won’t have the capacity to help, unless you plan to buy a 256 GB SSD or larger. Then the drive will improve your system’s performance, reduce noise and weight, and increase battery life, if only by a few minutes.
And if you are still unhappy with the low capacity of SSDs, you can consider having a solid state hybrid drive as an alternative. They perform almost like an SSD with a higher capacity (750 GB for $150)