Specifications

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speed is always the faster rating because it is easier and faster to pick up data patterns than to
sort them and write them. The sizes of files and the number of files, however, will alter the actual
speeds. Writing or reading hundreds of small files will take longer than writing or reading the same
total capacity spread over several large files.
Flash Media Comparison
CompactFlash
Type I
Smart Media
MultiMedia
MMCplus
Secure
Digital
Memory Stick
xD Picture
Card
ThumbDrive
USB 2.0
Present max
capacity:
16GB
128MB
2GB
8GB (plus)
2GB /32GB
SDHC
8GB
1
1GB
2G
read speed
(MB/sec):
up to 40
up to 1.5
up to 1.7
up to 40 (plus)
up to 16
up to 1.8
up to 60 (HG)
up to 5
20.0
write speed
(MB/sec): up to 40 up to 1.5
up to 0.3
up to 25 (plus) up to 9
up to 2.45
up to 15 (HG) up to 2.5 11.0
weight (grams):
11.4
1.8
1.5
3
4
2
12
max shock:
2,000 G 1,000 G 1,000 G 1,000 G 1,000 G 1,000 G
number of pins:
50
22 (contacts)
7
11 (plus)
9
10
NA
advantage:
large capacity
thin;
lightweight
small size
small size
small size
small size
small size
widely
compatible
relatively
inexpensive
works in SD slots
write/protect
switch
write/protect
switch
write/protect
switch
write/protect
switch
Rugged
portability
disadvantage:
size; weight
lacks
controller
slow write speed
cost
little support
beyond Sony
devices
Supported
only by
Olympus and
Fuji so far
slow transfer
speeds
large profile
less durable
commonly used
in:
professional
digital cameras
Fuji, Olympus,
Toshiba
cameras
MP3 players
cameras,
camcorders
Sony cameras,
first use in
new Olympus
and Fuji
cameras
laptop
computers
voice recorders
MP3 players
camcorders
printers
Nokia mobile phones
Cell phones
Sony devices
Palm PDAs
Laptop
computers;
Palm PDAs
1
Memory Stick Pro and Pro Duo can hold as much as 8GB, but the standard Memory Stick has a maximum of 256MB in two banks of
128MB accessible by switching between the two banks.
The actual speed depends on the design of the controller chip in the card as well as the design of
the reading/writing device. Faster flash cards may make no difference in digital cameras whose
own internal processing of images is far slower than the card’s transfer speeds. As capacities of
flash cards grow, however, and cards are used for storing much more information, read and write
speeds become more significant. Some newer digital cameras rely on the fastest speed of cards
to record video. Slower flash cards may not be able to provide the video feature on such cameras
although there would be no such restrictions on standards photographs.
NAND Flash Speed Restrictions
Although NAND flash devices are commonly described as writing data randomly, random writing is a form of
sequential writing in little, random sections. In digital terms, a “blank” flash memory device contains only the
“1’s” in the digital choices of 1’s and 0’s. Data are stored in the form of adding electrons to prevent certain
cells from passing electricity so that they become “0’s.” To change a zero to a one, the entire block of NAND
Figure 16