The memory card speed, is the card's performance with regard to how quickly data can be transferred to or from it. The card speed is often stated in "times speed" ratings i.e. 12X, 40X etc (just as the speed of recordable CD's and DVD's is measured), and sometimes more specifically in megabytes per second (Mb/s).
x1 "speed" is equal to 150kb/sec data transfer, so a x10 speed memory card would be 1.5Mb/sec
SanDisk Memory Cards use the MB/sec rating on their cards and packaging, however some other manufacturers such as Lexar and Transcend have adopted the speed rating system and use x133 to rate a card that is 20Mb/sec.
By today's measure, sub 60X represents a standard speed, 60X to 133X is mid-high speed and over 133X is high speed. The chart below shows the relationship between the two figures.
Rating | Write Speed (MB/sec) |
|---|---|
6× | 0.9 |
10× | 1.4 |
13× | 2.0 |
26× | 4.0 |
32× | 4.5 |
40× | 6.0 |
66× | 9.0 |
100× | 15.0 |
133× | 19.0 |
150× | 22.0 |
200× | 29.0 |
266× | 39.0 |
300× | 44.0 |
400× | 59.0 |
600× | 88.0 |
(Figures are based on 1024kb per MB - figures are rounded up/down)
Why are different or higher speeds cards needed?
High speed memory cards become more and more useful in higher resolution cameras and camcorders, as file sizes increase data transfer becomes slower, so by using higher speed cards data transfer speeds increases. If lower speed cards are used in high megapixel cameras the file sizes are too large, meaning when you press the shutter there is a time lag between pressing the shutter and being able to take another photo. Similarly, when transferring data from the memory card to a PC or Mac, a higher speed memory card will transfer the files much quicker.
Who needs high speed memory cards?
Pro photographers and enthusiasts using professional grade cameras such as digital SLR's should use high speed memory cards of at least 133X / 20Mb/sec speed. If you own a camera with a megapixel rate above 6 million pixels, you will certainly benefit from a card with a higher speed rating. If for example, you are using a compact camera under 6 million pixels, you'll get great performance from standard cards with 60X / 9Mb/sec or more.
If you need helping choosing the correct memory card for your camera or camcorder, please take a look at our accessory search, here we have listed thousands of devices with recommended memory cards and other accessories. If you need more help please call the office.
