When is a Gigabyte not a Gigabyte? Well, that depends on who you ask. Because USB flash drives are still a developing technology, standards for them are not yet set in stone. Good thing you can count on the Tech Guy to provide you with the straight truth about USB drives! Hopefully I can clear up some of the mystery surrounding speed ratings, storage capacity, and performance requirements.
Truth in Numbers
How is it that two competing companies can both produce “high speed” USB flash drives, and one will be faster than the other's? This question has a three-part answer because there are many chances for the truth to get skewed.
Not all USB flash drives are created equal, though they all contain a memory storage chip. Some manufacturers use Single-Layer Cell (SLC) memory chips and others use Multi-Layer Cell (MLC) memory chips. Single-Layer Cell memory is faster and has lower power requirements, but it is more expensive to produce. Multi-Level Cell memory is just the opposite; it has slower transfer speeds and uses slightly more power, but is much cheaper to produce. The retail price of a drive is often the best indicator of the drive’s performance, simply because the faster chips are more expensive to produce.
Next, the overall transfer speed of a USB drive can be limited by the memory controller on the drive. The memory controller is the brain of the drive and a key part in a good drive. Even drives with ultra fast memory chips can fall far below their potential if they have a slow controller.
The next most common misunderstanding is that USB 2.0 means “all fast - all the time.” This is misleading because the speed rating of 480Mbps has a small b in it, which means mega-bits per second, which translates into a peak transfer speed of 60 MB/sec. I say “peak” because USB 2.0 can transfer data at that speed but the nominal speed is lower, around 30-40MB per second (still very fast).
Finally, the way manufacturers test the performance of USB drives differs greatly. One may test on a “typical” desktop computer while another may test on a “high performance” gaming machine with newer and faster components. Manufacturers can also use different methods of testing transfer speeds, from specialized software programs to stopwatches.
Size Does Matter
Whether you are looking at buying a hard drive, a memory card, or a USB flash drive, chances are the package has a statement in the fine print about the actual storage capacity of the drive. Some manufacturers list data capacities in binary format and others list them in decimal format, because rounded and inflated values may be more appealing to customers.
So does your 1-Gigabyte drive hold 930 megabytes, 1000 megabytes or 1024 megabytes? In the traditional binary definition (based on the number 2), 1 GB is equal to 1,024 MB; however the decimal definition can be read as 1,000,000 Bytes, or 1,000 MB. Both values are commonly associated with the term “Gigabyte,” so a drive labeled “1 Gigabyte” could be either. For the straight truth on your drive’s capacity, always check with the manufacturer first and be sure to read the fine print.
How Much Is Enough?
Now that you know the truth about transfer speeds and storage capacities of USB drives, you might be wondering how much performance you really need. Is it worth the extra cost to purchase a high-performance USB flash drive?
The answer depends on how much you plan to use your USB flash drive. For the casual user who brings text documents and spreadsheets between the home and office, a standard drive is more than sufficient. Regular USB drives are also great for tasks like MP3 playback and storing digital pictures.
If you plan to use your USB drive on a daily basis, it may be worth investing in a higher-end model. High-performance drives are great for storing large video files, frequent read/write operations, and portable gaming (Starcraft, anyone?).
The last and possibly most important aspect is: Where are you going to use this drive? If you have an older computer, you may not even be able to reach the minimum speeds of USB 2.0 and you may not be able to reliably play your MP3s because your computer lacks the oompf to handle the job.
The Alpha USB drive from US Digital Media is a great all-around drive for anyone looking to get started with USB flash drives. Available in multiple capacities, the Alpha drive features a removable cap and a strong aluminum body that keeps your data protected at all times.
The important thing to remember about USB drives is that speed and capacity ratings can and do vary from one manufacturer to another. The best way to gauge performance is between different models within the same brand. Always check the facts and remember that if something seems too good to be true, it probably is. Take it from the Tech Guy, your expert in the USB business!