Features of Memory Cards for Digital Cameras Part 2

Continued from Memory Cards for Digital Cameras 1

Transfer Speed

Write and Read Speeds

Transfer speeds in memory cards for digital cameras are classified into write and read speeds. Flash memory normally is able to read memory at a faster speed than writing to memory. Therefore flash memory cards normally advertise with their maximum read speeds.

However, writing speed is important for digital cameras which can take high quality videos or take many photos in rapid succession.

During operations like these, the memory cards for digital cameras must be able to write data quickly to memory. If the write speed of the card is unable to handle such requirement, the camera function may be stopped abruptly.

Although most high speeds memory cards have no problem handling video capturing on cameras, the difference between high writing speeds and sufficient writing speed can be significant.

Users commonly transfer data from their memory cards to higher capacity media like computer hard drives. Given that capacities of memory cards are now as high as 8 GB, imagine waiting for more than 2 hours to download all 8 GB from a card of 10x write speed.

Certainly, a 10x write speed is sufficient for video, but not satisfactorily in data transfer.

Latency

Another important feature in transfer speeds is latency. Latency occurs due to the time needed by the memory card to retrieve information for writing or reading the card. Latency in flash memory is not as significant as in hard drives.

Hard drive memory cards normally idle when not in use to save power. When reading or writing is required, the drive spins but some time is require before the drive is able to be read.

If data is highly fragmented in a hard drive, retrieving of information can also be delayed. Defragmentation can help hard drives in reducing latency.

However, flash access memory in a random access fashion, therefore defragmentation does nothing for flash memory. In fact, defragmentation causes unnecessary write-read cycles for flash memory, harming its product life.

Memory Cards for Digital Cameras