Selecting Right SD Card for your Device
Secure Digital Cards (SD) are available in sizes ranging from 128MB to 2GB. While I am writing this guide most common sizes is 1GB being flash prices has been reduced. However this guide is for customers to understand different SD cards available in the market and why they have pricing difference.
1. Choosing right Speed
SD cards are available in various speed, when we talk about speed it's the transfer rate of data from the device to the memory card for writing or from memory card to device while reading. The controller and geometry of SD Cards determine the speed they would be able to provide. Let me explain geometry.
SLC and MLC are two different types of Geometry that exisits for them. Without going in technical stuff, all I need to say that SLC are single layer and are faster whereas MLC are multi layer and slower cards. SLC therefore are expensive.
Kingston today offers following range of the SD cards
a. Standard Speed
b. Elite Pro Series (50X~55X)
c. Ultimate Series (120X)
Similary Sandisk, which are another popular brand has
1. Standard Cards
2. Ultra II
3. Extreme III
According to the speed each company has categoried their cards into above series. Although they do not publish more technical information but I can say the standard series are slow cards. Consider them if you are going to use them for Camera's less then 3 MP or using them into mobile phones or PDA where you do not need high speed access.
IF you are using high end camera's where you need to save images more then 3MP consider using higher speed version of these cards. Meanwhile if your demands are like that for sports photography where you need continous shoots dont compromise anything lesser then for the Ultimate series which can quench the thirst. Elite Pro series are just right balanced cards which 55X speed and serve general purpose camera, PDA and GPS systems.
Certain Video camera's use SD Cards for the video recording, this involves lot of data to be saved in fast streams, consider using Ultimate series as well for such purpose.
However there are many OEM Cards available, cards like from aData, RiData, Samsung, e-Xcessories. You need to check for the speed for these cards from the specific vendor and not just the price they are offering for the same size. Buyers most of the time get biosed with the pricing when buying oem type cards and might get cards which are slower and do not really perform upto the level expected.