Crucial flash speeds — the 'X' factor
How fast is it? That's one of the most common questions we receive regarding our flash memory. And here's the answer, in a nutshell.
The speed of flash products is rated with an X (such as 40x): the higher the number, the faster the product's write speed. (It's like the rating you see when buying CD-ROMs.) Not all flash sellers use the same speed rating system, however. Some don't rate their products at all, while other rate them by the read speed, which is always faster than the write speed — or the data transfer rate. The write speed is the true indicator of how fast a card or UFD can move data.
How is the X speed calculated?
The speed rating system is based on the optical drive industry's system. A data transfer rate of 1X means that a product can transfer data at 150 kilobytes per second.
What does this mean for performance?
Although actual speeds vary, based on factors like the quality of the flash product, the speed of your host device, and the size and settings of your files — it's possible to make a reasonable estimate for read/write performance.
Let's say you've taken 30 high-resolution pictures on your flash card, each one 3.5MB in size. Theoretically, the flash card would read/write data at the following speed ratings
| Speed Rating |
Transfer time of 30 high-resolution pictures at 3.5MB each |
| 40X |
18 seconds |
| 80X |
9 seconds |
| 133X |
5 seconds |
| 300X |
2 seconds |
It's important to note that a higher speed rating is not necessarily better. Just because a product has a particular rating does not mean it will transfer data at that rate in every device. That's because flash memory is a lot like the memory in your computer — you can have the fastest memory on the market, but if your PC isn't designed to run it, that memory can't reach its full potential. The same rule applies to digital devices such as cameras, cell phones, flash card readers, or USB ports. You're only as fast as the interface.
How do you know the speed of your camera or digital device?
Determining the speed of you device can be tricky. Most manuals don't tell you the speed of the flash card you should buy. Here's a general rule of thumb: if your camera has a pixel count of less than five megapixels, the speed rating of the flash card doesn't matter much. The improvement you're likely to see in a higher-rated card will be minimal-just fractions of a second.
Ratings for USB Flash drives
The performance of a USB flash device is dependant on the speed of the USB port in the host device as well. When you plug a UFD with a higher X speed into a USB port with a slower X speed capability, your UFD will transfer data at a slower speed to the port.
Why you should buy flash memory direct from the manufacturer?
While flash memory is extremely durable, it's best to buy from someone you trust. Lexar is the only memory upgrade supplier that's part of a major flash and DRAM manufacturer, Micron. Our UFDs are compatible with most USB-enabled computers — desktops, notebooks, Macs, PCs — any system running at least Microsoft® Windows® 2000, Mac® OS 9.1, or Linux kernel 2.2.19. But if you don't know what kind of flash card your device uses, we make finding the kind of card that's compatible with your specific device is easy with our
Flash Memory Advisor tool, located on the Crucial Web site. Just pick the make and model of your electronic device, and we'll tell you what flash memory card is right for you!
Buy your flash memory from a reputable dealer that stands behind its product — all Lexar flash products are backed by our renowned service, support, and limited lifetime warranty.