SSDs versus HDDs: Is it worth the upgrade?

By Mike on 12:16 pm

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There's been a lot in the news regarding new solid state drives lately. Essentially, they're like flash drives on steroids. They use flash memory to store data in a non-volatile manner and function just like a hard drives. They are set to replace hard disk drives in the near future, but are available on the market now for consumers to purchase. The question is whether or not to upgrade your system to solid state, or if it makes more sense to wait a while.

Hard drive technology is quite old, dating from at least the 1960s. Inside the drive is a set of spinning metal (or metal coated glass) platters and a read/write head that uses magnetics to store data. While they've improved a lot over the years, we are beginning to reach the limits of what this technology is capable of. Perpendicular recording has increased the amount of data a 3.5'' hard disc can store up to 1.5tb while 2.5'' mobile drives have increased to 500gb. However, the drives still have fundamental problems. With any mechanical system, heat and noise are always a problem. Excess heat and vibration causes premature wear. Mechanical systems also have inherent durability issues. If you drop your laptop for example, the read/write head of the hard drive could grind into the disk platters and permanently toast your data. Most laptop drives have shock sensors now that park the head if they sense a fall, but the issue still exists. Hard drive failure rates can also be all over the map depending on how the drive was made and who made it. Hard drives, also have limited data transfer rates and high seek times due to the inherent mechanical nature of the system.

Solid State Drives seek to address the fundamental issues with mechanical hard drives. Namely, they don't consume a lot of power, they don't generate a lot of heat, and they're much more resistant to physical abuse. Some companies have already taken the liberty of installing them into some systems. Apple was a notable pioneer in the full size laptop market when they released the Macbook Air with a solid state drive option early this year. All Apple laptops now offer them as an option. Lenovo has also begun offering SSDs as an option in their venerable Thinkpads. Asus also pioneered the market when in 2007, they made them standard in their early EeePC systems. The question is whether it makes sense now to replace your hard drives with an SSD, or is it better to wait. The advantage with SSDs is performance. In a hard drive, the read head has to physically move to find data on a platter and it can only transfer it as fast as the platter can rotate. With laptops, there's always been a tradeoff between performance and energy savings, meaning slower rotation speeds are used, meaning slower data transfer rates and seek times. With a solid state system, it has no moving parts meaning seek time is virtually nill. Transfer rates are also potentially faster. Hard drives have always been the weakest link in the performance chain but Intel claims their SSDs can read data at up to 250MB/s, which is the realistic top speed of the SATA bus. Rate of wear has also improved. Flash memory does deteriorate over its lifetime as data gets written and erased, but they now match the MTBF of mechanical hard drives.

Sounds great, so where do I sign up? Well, things aren't that peachy. The biggest flaw of SSDs so far is that they're vary expensive. Lower end, slower ones can cost at least double the price of mechanical drive. These "cheap" SSDs also cannot match the raw read and write rates of their mechanical counterparts. Write rates in particular can be much slower than a traditional HDD, especially where large files (ie video files) are concerned. The lightning fast seek times do counter this somewhat but still, you may be paying significanty more for less performance. Storage capacities are also limited. The biggest consumer SSDs top out 250GB and these cost up to $700 or more. If speed is what your after, Intel's 250MB/s drives cost just as much, for only 32gb. By contrast, Western Digital's venerable VelociRapter 10,000rpm 300GB drive costs about $250. Even faster SCSI and SAS drives that run at 15,000 RPM are available, and they're still cheaper dollar-to-gigabyte. The third issue is Windows. Microsoft's operating system has been optimized for hard drives and reportedly, it doesn't always agree with SSDs, especially if they're the boot drive. Because of this, performance is less than it should be. I would assume that both Linux and Mac OS X don't have issues with them.

So, is it worth it to upgrade to SSDs now? I'd say not yet. While this technology is certainly the wave of the future, they're just too expensive right now and real performance improvements for cheaper consumer drives are dubious at best. If you want performance, it makes far more sense to purchase high performance 10,000rpm hard drives for desktop systems. In laptops, SSDs do make more sense. I would recommend them if durability is a concern. However, it's best to just save your money and purchase cheaper mechanical drives. Wait for the price to come down to something more reasonable first.

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