The tiny miracle of microSD cards (Part 1)
Paul Ockenden carefully looks over memory, SSD drive, and so on.
Normal readers will show that this
title is related to smaller and faster electronic devices more than ever,
although it is smartphone, laptop, netbook, tablet, or any other mobile device.
This month, I want to study in smaller details by considering the highest
development in the memory card.
In the mid of 1990s, I remember
being surprised at 2MB CompactFlash memory card and wondering how its producer
(SanDisk - if I do not misremember) can stuff too much capacity into such a
small package. After one and a haft decade, a 32GB microSD memory card
contained the capacity as 16,000 times as much as it in a pack just counting
for 3% of the old memory card’s physical size. These statistics make the Moore law rather boring in comparison.
Actually, I will say that microSD
memory card is one of the great symbols of the current technology
accomplishments. Its shape coefficient is small enough to be extremely mobile –
as the size of a nail – but still large enough so as not to be too difficult to
process. The capacity is extremely large (64MB in maximum at current, but let
that barrier be broken a few times in this year), and it is not expensive: a
basic 32GB microSD memory card is about 40 USD. Think about that when your
tablet provider charges 150 USD for a 64GB model in comparison with 32GB model
– and yes, I am looking at you, Apple.
Another plus point of microSD: it
is a general storing form that you can plug in smartphone or tablet (some), or
through cheap SD/mini-SD adapter and simple card reader device, you can put it into
camera and laptop. Why does it have to be involved in cable and driver when you
can transfer file directly from memory card to PC? It is easier, has fewer
errors, and is nearly faster than sending file through USB connection.
If this makes everything sound
attractive, allow me to say a small note: not all microSD memory cards are
similarly created (a really right thing for all memory card formats, not only
for microSD). First, in an extent related to speed, they are considerably
different. Many cheaper memory cards belongs to Class 2 or Class 4 (usually you
will see the C character with number 2 or 4 inside, printed somewhere in the
card), and this classification is quite clear since Class 2 means device can
accept write speed at 2MB/second, while Class 10 will record file with the speed
at 10MB/second. It can be much easier to understand in comparison with the old
X index usually seen on memory card (for example, 33X or 100X) that always
sounds difficult to understand.
2MB/second of Class 2 approximates
to 16Mbytes/second, which is slower than ADSL of anyone nowadays. If you want
to use the card in a DSLR camera, especially the one with the high burst
shooting speed, certainly you will find that Class 2 or 4 is so limited, and
these slow memory cards can also be struggling to record 1080p video in high
fidelity. There is Class 6 memory card, but you have almost not ever seen a
card at that speed, and I do not know the reason why. Most producers jump
directly to Class 10, and there are higher prices for these faster memory cards,
although you can find snip if taking pains to looking for. For example, Shopbot
sells microSD Class 10 memory card (16GB) with 22 USD.
I see it is the best to choose
16GB capacity, since it is quite well-supported by current devices. You will
see that some phones are rather shaky if provided 32GB memory card, a problem
that is even commoner than the 32GB one, while the 16GB works well at anywhere.
For example, Amazon sells a Class 10 memory card (16GB) of Samsung with the
estimated delivery time from 1 to 3 months, which is quite exact – I ordered
one on Sept, 15th and received it at the middle of Dec. It is quite
long but it is worth waiting because of a good price and being a very fast
memory card from a senior producer.
And that takes me to the next note
– please be careful of those from whom you buy microSD card (or any flash
memory card) since there are many fakes. Particularly, eBay has a lot of memory
cards claimed to be in 32GB or 16GB, and actually it reported the capacity as
it was inserted into phone, PC, or camera. However, in reality, it just
contains 4GB or similar useful memory. You will take a few pictures or save
some MP3 files, and everything appears to work well, so you think that you
bought a snip. Only when the device is full can you recognize the files are
corrupt.
Sometimes capacity is right, but the
card marked Class 10 is actually Class 2 speed. It is real that a memory card
named Samsung or SanDisk does not make sure it is genuine, except you buy it
from a reliable source. I do not imply that all memory cards sold on eBay are
shoddy goods – not at all, since there are many honest sellers using eBay as a
place to do business. However, it is too easy for an innocent buyer to buy
shoddy goods, so apply preventive measures on eBay: make sure that sellers have
good feedbacks (in particular, look for comments such as “fake” or “cheat”) and
choose local sellers rather than sellers from the Far East. It is necessary to
be vigilant when buying memory cards from marketing places or sellers
advertising on websites such as Gumtree.
If you are not sure of the quality
of the memory card that you bought, there is a free intelligent software named
H2testw 1.4 that you can download from http://tinyurl.com/2f4tr6. It is written by a person called Harald Bogeholz, and is
considered as a gold standard when we mention memory card’s speed and capacity.
The author is German, but so luckily, when you run the software, there is an
English option that fills up the card and confirms its real capacity, as well
as checks its read and write speed. It is a wonderful software – you just need
to know that depending on memory card’s size and speed, it takes a while to
run. It is very useful when you can check doubtful memory cards in this way,
but when talking about buying memory card, certainly it is the buyer that is
responsible for the item he received.
