Questions: What is a Memory Card?
First things first - what exactly is a memory card? Memory
cards were developed because many digital products, such as
digital cameras, videos and mobile phone, required some form
of storage for their data and the ability to transfer files
between compatible devices. A special slot or port for
inserting a memory card is included on digital devices.
Memory cards are small, portable storage devices that use a
type of electronic memory called 'flash memory' to store
different types of electronic data such as images, video and
audio clips and text documents.
Questions: How Safe are my Memories?
Memory cards have major advantages over other storage
storage devices such as hard disks or DVDs/CDs. Memory cards
are less fragile, much more shockproof, less prone to damage
from movement and can easily take a couple of scratches
without loss of data. Memory Cards are Reliable, Removable
Questions: How do I Transfer Data from a Memory Card to my
Most computers are built with multiple slots or ports for
transferring data. If your computer is equipped with an SD
slot, you can transfer your data by simply inserting your SD
memory card. If your computer does not have an SD slot, or
is built to an earlier SD standard than your memory card,
you can use a USB reader/writer or computer card adapter to
easily transfer data from your memory card to your computer.
Questions: What is Flash Memory?
Flash memory a type of memory that retains data in the
absence of a power supply (non-volatile storage). Flash
memory was developed in the late 1900's as solid-state chip
technology used for storing digital data and gets its name
because the microchip is capable of erasing a section of
memory cells "in a flash". Flash Memory Cards have many
Memory Cards are very tough and will not
break if dropped - they are both secure and
Memory Cards are removable and re-useable
Memory Cards are shock resistant, Freeze
resistant and X-Ray proof ensuring the
safety of your memory card content
Memory Cards are extremely compact and can
store gigabytes of data in a very small
Memory Cards are very fast and have no
moving parts and Flash does not need battery
Memory Cards allow data to be written and
re-written and is not erased when the power
is shut off
Questions: What is Non-volatile Storage?
Volatile Memory loses its contents when the power is turned
off whereas Flash memory provides non-volatile storage (NVS),
which means that a power source is not required to retain
stored data. Nonvolatile storage means that data stored on
your digital device will be stable and is not subject to
corruption or loss in the event of a power failure.
Questions: Why are there different Shapes and Sizes of
Memory cards have different storage capacities and transfer
speeds. The card dimensions follow one of the many standard
shapes in order to fit the devices that they are meant for.
All memory cards are compact items, as thin as a credit card
that range between the size of a postage stamp to a
matchbook size. There are numerous
types of Memory Cards
for sale, but the SD (Secure Digital)
range of cards are the most popular, especially for the
'point and click' cameras followed by the Micro SD cards for
Questions: What are the different Capacities of Memory
Capacity refers to the number of bytes a memory card can
hold. Memory cards store gigabytes of data in an extremely
small space. In order to accommodate evolving technology and
consumer needs, different variations of memory cards have
been developed featuring a range of capacities, and
generally, the more memory or capacity available on a given
card will often mean a higher price tag.
Questions: What are Gigabytes?
Gigabyte (GB) is a unit of measurement approximately equal
to 1024 megabytes. Gigabytes are commonly abbreviated GB in
writing and referred to as "gigs" in everyday speech.
Computer components process data in bytes or multiples of
bytes such megabytes (~1 million bytes), and gigabytes (~ 1
billion bytes). Memory cards indicate storage capacity as
1GB, 2GB, 4GB, 8GB, 16GB, 32GB and 64GB, but as technology
marches on capacity will soon be indicated by Terabytes (TB)
a thousand billion bytes - that is, a thousand
Questions: SD (Secure Digital) Cards
most common type of flash memory card is Secure Digital (SD),
which include SDHC (Secure Digital High Capacity) or SDXC
(Secure Digital ‘Xtra Capacity’) cards. SD also includes the
ultra-small MiniSD and MicroSD formats.
Questions: The History of SD Memory Cards
history of SD Cards evolved to meet the needs of consumers
and new digital technology
1999: Original SD
cards (Secure Digital) were released in 1999 but only went up to 2GB, so SDHC
(Secure Digital High Capacity) memory was
2003: In 2003 Sandisk released the MiniSD as
an extension to the SD card standard
especially for smaller electronic devices
like mobile phones and tablets. MiniSD cards
are usually packaged with a MiniSD adapter
that provides compatibility with a standard
SD memory card slot
2005: Physically smaller cards, called
MicroSD were then developed for storing
images up to 2GB on mobile phones. Micro SD
cards were released in 2005 and were 80%
smaller than standard SD memory cards
2006: SDHC was released in 2006 with a
maximum capacity of 32GB that increased to
64GB of storage
2007: Micro SDHC was released in 2007 to
provide increased speeds over MicroSD
Higher capacity and faster processing speeds were soon
required so the SDXC (Secure Digital ‘Xtra Capacity’) was
developed and released in 2009 with a storage capacity from
64GB to 2TB (Terabytes)
Cards: SDIO (Secure Digital Input Output) cards
SDIO (Secure Digital Input Output) cards were developed for
use with products that needed an input and output function.
SDIO cards have the same connections as standard SD cards but will
not work correctly with devices not built to the SDIO
standard. However, these cards will not cause damage if fitted in
error to a device not supporting the SDIO standard.
Questions: Ultra High
Ultra High Speed (UHS) bus design for SDHC and SDXC cards
was added to increase the performance of SDHC and SDXC
cards. A 'Bus' connects input/output or I/O to Processor and
(CF) Memory Cards
CompactFlash (CF) cards
were initially developed in 1994 for advanced DSLR (Digital
Single-Lens Reflex) professional cameras, but were also
high definiton (HD) video cameras, to provide
faster processing times with even higher storage capacities
with a large 128GB maximum storage capacity. Compact Flash
cards are larger than SD cards, can record at a faster rate
are extremely tough. CompactFlash (CF) cards may also have a
UDMA (Ultra Direct Memory Access) rating. UDMA refers to the
technology the card uses to enhance its speed.
Questions: MultiMediaCard (MMC)
The MultiMediaCard (MMC) provides a maximum of 4GB of
storage. MMC is no longer a supported standard as the last
revision of the standard was in 2005 and most cameras do not
accept MMC formats.
Questions: Reading and Writing Speed
Memory Cards are not just about capacity, they are also
about writing and/or reading data to and from a memory card
- and how quickly this can be done. The speed of memory card
will determine how fast and how many photos or videos can be
taken in rapid succession. 'Writing' is the process of
transferring data - how fast photos and videos can be saved
on to a card (you will need a fast writing speed if you
enjoy shooting HD or continuous bursts of action
photography). 'Reading' is the process of transferring data
from a memory card to a computer and indicates how fast data
can be retrieved from a card. Read speed is faster than
Questions: Speed Rating
- Class 2, Class 4, Class 6 or Class 10 on SD Cards
you are using SD cards, the speed of the card is rated as a
class rating. The
class is the speed rating which measures maximum transfer
speed for reading and writing images to and from a memory
card, expressed as megabyte (MB) per second. Speed class
rating is important when using HD video mode or camcorders
when a steady stream of data is being saved. Memory cards
specify Class 2 (slowest), Class 4, Class 6 or Class 10
(fastest) on SD Cards.
product asks for a
minimum Class 4 memory card you can use Class 4 or above
without any problems
If your device requires a Class 6 card
you can use a Class 6 or a Class 10 card in most products
device requiring a Class 10 card needs the speed to enjoy
the best performance.
Questions: What is Backward Compatibility?
As products such as digital cameras, videos, cellphones etc.there are compatibility issues
to consider. Devices that only accept the original SD
(Secure Digital) card format will not be compatible with
SDHC (Secure Digital High Capacity) or SDXC (Secure Digital
‘Xtra Capacity’) memory cards. However, both SDHC and SDXC
memory cards are backwards compatible, enabling them to read
previous formats. A device is backwards
compatible if a product designed for the new standard can
receive, read, view or play older formats and standards.
can only use SD memory cards
can use both SD memory cards and SDHC memory cards
can use SD memory cards, SDHC memory cards and SDXC
Questions: How do I Unlock my Memory Card?
There is a locking switch on the left side of the SD Card
which prevents data from being read, written, and deleted
from the storage card. Check that the Lock switch is slid up
which will place the card into the unlock position.
Questions: How Many Memory Cards do I Need?
There are so many devices that now take memory cards - even
pet tags use them! A memory card is re-useable and will give
many years of service but additional cards will provide you
with increased flexibility.
Extra memory cards are useful when you're
unable download your pictures, e.g. when
you're on holiday, or away from home
Don't run the risk of running out of storage
space - Remember that shooting videos takes
up lots of memory
Spread the risk of losing a card by using 2
or 3 memory cards with your device
"Memory is like chocolate
- you can never get enough of it!"