It is a standard brought over from optical media recording. Whereas when the speed is mentioned as 600X or 1066X what exactly does it means? X means 150Kb per second.

When it comes to CF cards the speed is often mentioned as X times and in many cards it’s been mentioned as MB per second, which is pretty straight forward. UHS memory cards have a full higher potential of recording real-time broadcasts, capturing large size HD videos and extremely high quality professional HD. If you use a UHS memory card in a non-UHS host, it will default to the standard data bus and use the “Speed Class” rating instead of the “UHS Speed Class” rating. UHS utilizes a new data bus that will not work in non-UHS host devices. Later, in 2009 another class, UHS, was introduced by the SD association and is designed for SDHC and SDXC memory cards. You really need to give weight to this one single-most important factor, when you buy a memory card. The speeds are primarily meant for video recording, where sustained recording (write) is required and it is supposed to be the minimum worst case scenario speed. The speed of cards have been classified into classes by the SD Association, which are referred to below. There seems to be a promising future for this card! Compact Flash card (CF card) It is even possible to geotag your photographs with the available wireless service, but with less accuracy though. This allows you to transfer the data to your computer or a cloud-based service or even to your Smartphone directly, thus enabling you to clear off the memory as you shoot, without having a need to replace the memory card. These are unique SD cards that come with built-in WiFi.

This type of card offers up to 2TB and increased transfer speed. The recent third iteration of SD card been announced in 2009 as SDXC cards (XC stands for extended capacity).

But as the time and technology progressed a later version as SDHC is introduced with a higher capacity of 64GB in 2006 (HC means Higher capacity). The initial high capacity is only 2GB when introduced in 1999. The constraint in using this card is the capacity of the card. This type of the card is widely being used in digital cameras, primarily in point and shoot cameras and secondarily being used in professional cameras.

Canon digital camera card reader