Hard disk drive technology has matured over the years, with drives spinning faster, achieving greater data transfer rates, improving at error checking, and attaining tremendous storage capacities. Those gains, however, have come at the cost of increasing disk fragility. Older SCSI and ATA drives could pretty much be counted on to safely store data for up to a dozen years whereas modern drives have a life of five to seven years.
In recent years, a new technology called flash technology has the speed and reliability of RAM, married to the permanent storage capability of a hard drive. We first saw these appearing in the form of flash cards for cameras, or “thumb drives” for computers. This same technology, scaled way up, is used to produce solid-state drives (SSD), which can finally serve as a replacement for hard disk drives (HDD).
SSDs operate at many times the speed of conventional HDDs – speeds approaching that of RAM and microprocessors. They have no moving parts at all. So, there are no friction or the vibration failures one sees in HDDs.
Daniel Cerveny and I were supplied with a 120 GB 2.5″ Kingston SSD. I conducted tests on it using my MacBook Pro as a test-bed, and then handed it over to Daniel for testing using a PC laptop of similar speed. The results of the tests turned out to be comparable between the two platforms, as we will illustrate below.
Operating System Installation
After I installed the SSD in my laptop, I formatted it, and installed MacOS 10.7 on it, a task that takes 21 minutes on a standard HDD. It took 21 Minutes on the SSD, also. Windows performed similarly, completing the installation in 26 minutes with both drives. In both cases, the limiting factor was probably not the speed of the drive, but rather the installation media.
Many of our senior administrators have sensitive material on their computers and are required to encrypt their drives using Apple’s FileVault, Microsoft Bit-Locker, or the TrueCrypt freeware. This applies a 128-bit AES Encryption to the entire drive – a one-time only, hugely time-consuming task that typically takes almost a minute per GB on a standard HDD. In the Mac test, a 160 GB drive required 3 hours and 9 minutes to be fully encrypted. The SSD managed it in just 18.5 minutes. The results seemed a little too good to be true. When I looked into why this was, I found it was because an SSD only encrypts the portion of itself that’s in use while storing the encryption key to apply to new sectors as they’re activated for storage. That doesn’t detract from the impressive performance, though!
The PC tests were performed using TrueCrypt, with the HDD clocking in at 3 hours and 26 minutes, and the SSD coming in at just over 29 minutes. An important thing to note about the way TrueCrypt encrypts SSD drives, is that when performing a full drive encryption, it is recommended that the drive is encrypted before any sensitive data is moved to it. Because of the way wear leveling works on an SSD, it is possible that files already on the drive will not be encrypted.
Large Data Block Transfer
This is the meat and potatoes in my line of work – moving data to and from a server or external drive, using USB 2, or Firewire 800. I connected my laptop to a server via a Firewire 800 cable, started it up in target-disk mode, and moved a folder containing about 61 GB of data. Using a standard HDD, this transfer took 21.5 minutes – the SSD performed better at 17.5 minutes, but I was still disappointed, given the SSD’s reputation for speed. Again, however, the speed of the Firewire interface, the internal buffers, and the server itself, limited how quickly the operation could be performed.
The PC test involved moving 66 GB of data from a folder shared on the network. The HDD performed the transfer in 26 minutes, while the SSD did it in 17 minutes. While 9 minutes may not be impressive, it is noticeable, and a welcome improvement.
Time to Boot
Finally, a small task that annoys everyone is the time it takes to boot the computer! On the Mac, the SSD made it from cold shutdown to the desktop in 16 seconds; a standard HDD did the same in 42 seconds. The PC results were more dramatic. While the HDD booted into Windows in a frustrating 3 ½ minutes, the SSD accomplished the same task in only 40 seconds. Here, where we are performing a task limited only by the capability of the drive, the RAM, and the processor, the SSD really comes into its own. Booting the computer, however, is not the only time the SSD would be able to run free: we could expect the same performance during photoshop or video renders, or other tasks not dependent on an external component.
Perhaps the most serious drawback to SSD technology is the cost. In a survey of currently available drives from different vendors (Newegg.com, and Tigerdirect.com, among others), I found the price per GB of SSDs was roughly double the price for standard hard disk drives. Fortunately for all, this drawback is a fleeting one: as this technology matures, the price can be expected to trend sharply downward, very quickly. Among other things, manufacturing an SSD requires far less human intervention, and far fewer steps than does manufacturing a standard drive with platters and read-write heads!
The only other serious draw-back to SSDs involves their capacity: currently, the highest capacity SSD one can find is about 500 GB, while conventional drives of several terabytes are available. As with cost, however, this drawback will only be a temporary one: as the technology matures, higher capacities will be available. Given the compact size of the drives, even when the capacity of the chips is reached, it will be a simple matter to combine a number of small drives into a single unit of very high capacity. At this point, we’ll also have the option of using RAID formatting for situations where the safety of the data is more important than capacity of storage.
For those on a tight budget or those in need of high storage capacity, the drawbacks of SSD technology outweigh the speed benefits. We expect this to quickly change. I predict, as early as next year, we’ll begin to see drives of high capacity and blinding speed available at comparable prices of conventional drives.Tags: hard drive, Solid-State, SSD, storage