The storage market is much controversial today. On the one hand, data
rates of the storage devices are growing very rapidly: we got used to kilobytes
per second for disk storage units, and now they offer dozens of megabytes
per second. Recently a drive for double-density floppy discs could be a
main disc drive of a computer, but now even much more efficient drives
are considered inappropriate for data transfer (even flash drives are needed
speedier - many expect USB 2.0 devices though this interface was born less
than a year ago). And what about optical discs? Well, the trend is the
same.
On the other hand, the speeds are growing slower than they should. Ten
years ago a 200 MB HDD was enough for an average computer, and today 40
GB is just an entry level. The memory size requirements have increased
marginally. For example, Windows 3.1 required 10 MB for installation and
the XP needs a partition at least of 1 GB. Other packets gained weight
as well, there are such new classes of computer tasks that users of the
past couldn't even dream of (just take video processing). That is why speed
will keep on growing.
No wonder that this processor involves less conventional storage devices
such as flash cards. Not so long ago pioneers of digital photography made
low-resolution shots, and at that time 4-8MB cards were enough. Today entry-level
cameras have at least a 2MP resolution and one shot even in JPEG takes
about 1 MB. Much improved optical systems allow using digital photo cameras
in professional sphere. But JPEG doesn't suit for polygraphy because of
compression with losses, and it's often replaced with greater TIFF. For
example, the Olympus E10 makes photos of about 12 MB. Some of the latest
models lift it up to 20 MB. Well, memory cards less than 256 MB do not
suit.
So, there are two problems we are to tackle today: pumping data from
a card to a computer and recording data onto a card as fast as possible.
The first problem is not so urgent, but the second one... Let's image we
are to shoot a fast-developing process. The solution is obvious: a series
of shots. Here a record speed is vital. For example, it's 500 KB/s, - in
this case the E10 will be able to make only a couple of shots for a minute.
Well, you can just press the release button and hope the most interesting
thing will happen exactly at that moment. 1 MB/s will give us 5 frames
per minute. 2 MB/s - 10, which is a more or less acceptable solution (if
you need a higher fps you'd better go with a video camera :)).
Flash cards are however used in other devices as well, where high speeds
are also required. Although megabits (not megabytes) can be enough for
a player, one has to fill in the card in advance, which also takes certain
time. PDAs do not work with large files, and high speeds are not so important
here, but there is one more crucial parameter stepping forward - access
time. Here is the case: you have to find a file with certain text and you
know key words which can be used in search. For example, the card contains
10,000 files, so it will be addressed 10,000 during the search. And what
if the first results are not satisfactory? The search is to be carried
out once again.
So, speed of memory cards is of really great importance today. Why is
SmartMedia dying out now? This standard is poorly scalable in size and
speed. Why is MMC going to be replaced with SDC? One of the reasons is
that the MMC is far not a speed record breaker. Why is the CompactFlash
getting so popular today despite its drawbacks? These cards can have a
size up to 1 GB (which is really required today), low data storage costs
(which
is very important for sizable cards) and a high throughput of the
interface which makes possible to lift speeds of the cards for quite a
long time. Speeds of different CF cards are widely discussed in the conference,
and we have touched upon it but haven't carried out any tests yet. So,
it's high time to do it :).
How to test?
It's clear we need an objective result. That is why a digital photo camera
can't be used because a lot depends on the camera's electronic stuffing.
Besides, it's impossible to get all three key parameters (read speed, write
speed and access time) in exact numbers. Other portable devices do not
suit either. Well, let's go with a computer.
Certainly, we rejected card readers for serial and parallel ports right
away. The speed of USB 1.1 doesn't suffice for today (besides, USB-ATA
bridges have their own limitations). I know only one card reader with the
USB 2.0 interface, but I failed to get it. Besides, reportedly, its bridge
limits the speed to 3.5 MB/s. Although it's quite high, I don't want to
have any limiting factors here apart from a pure card speed.
There are three types left:
-
Card reader connected to the IDE interface. It is the most optimal solution
but we couldn't get it
-
PCI-PCMCIA adapter and passive CF-PCMCIA adapter. It seems to be a good
option but here much depends on the PCI-PCMCIA bridge. Besides, it's necessary
to get to the rear panel of the system unit which is not an enjoyment
-
Card reader with the FireWire interface. The FireWire-IDE bridge can bring
in problems, though this option is the simplest and most convenient.
So, I took the third way. The tests were carried out with the DataFab ImageMaster
MDCF-FW card reader. I must say that it doesn't differ from worthy USB
devices of this company except the connection way.
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By the way, we came across an interesting peculiarity of the ATi All-in-Wonder
Radeon 8500DV video card which wasn't mentioned in our review.
The integrated FireWire interface of the first revision of the device caused
a lot of problems when we used mainboards with Intel's chipsets. Moreover,
both ports can be used only with devices with their own power supply. One
the one hand, the FireWire can consume high current, which is not typical
of AGP. On the other hand, why wasn't that mentioned in the documentation?
However, if we use a port for connecting a video camera with its own power
supply unit, a scanner, a printer etc., it won't be a problem... but the
impression left is not pleasant.
The rest of the configuration is typical for today and doesn't affect the final
scores much. The computer was running under the Windows XP Pro; the
processor used was Athlon XP 1900+. In the tests I mostly use the HD
Tach 2.61 as the Winbench 99 can't calculate the write speed which is
the most important for us (recording of shots into a digital photo camera
is what must be done swiftly). Besides, this test has some troubles
in defining a read speed as well. I didn't feel any desire to copy different
number of files of different sizes as the results of this test under
the modern Windows version are hardly repeatable. And access time can't
be directly calculated. Taking into account that the HD Tach is a tough
cookie as well, I used three methods in case of a big difference, but
the results correlated well, so I left the HD Tach's data.
First of all, I put the Transcend 16 MB card I have been using for over
three years into the adapter. Here is what the HD Tach gives us (by the
way, Transcend always released very fast memory solutions, that is why
this long-liver can beat even new flash cards):
So, it doesn't make sense to use USB devices in the tests: while they are
able to show a similar write speed, such a read level can be achieved only
in theory. Modern cards can probably score better results. Furthermore,
you can stop reading this article if you use the USB interface or a slower
one to connect the card and computer, and:
-
use cards to exchange data between computers
-
never shoot in TIFF or RAW, especially if the camera used is not greater
than 3 MP
-
use a card only in a digital player
-
use a card only in PDA but don't store many small files
-
do all the things above altogether :)
In this case different cards do not differ much in speed because it's not
them that works as a bottleneck. The above tasks can be handled by old
cards, as the Transcend shows, not to mention modern ones.
But the speed aspect is important for those who:
-
use FireWire or IDE card readers or PCMCIA to exchange data with a computer
-
use uncompressed formats in photo shooting, especially in shooting series
and on high-resolution cameras.
On the other hand, I think you all should look through the results: in
equal conditions one should go with a faster device. Because it will be
impossible to increase speeds of the cards afterwards.
Tested cards
We tested 16 different cards of the CompactFlash Type I interface. There
are some more cards of this interface type that we failed to test, as well
as all Type II cards (in particular, IBM Microdrive), but I decided to
publish the results right now than to detain waiting for the rest to come.
For the tests we used mostly 128 and 512 MB samples. The first size
is optimal for budget users, the second one for "Power Users" (1 GB samples
are quite young and their price/size ratio doesn't look attractive). Besides,
it's interesting to reveal connection between the speed and size of cards
from the same family. Moreover, we could use no size as a guiding one because
not always all sizes are available. The Viking's solution (160 MB) stands
apart as this trademark is not widespread on our local market.
Since we got too many diagrams, here I will give you just photos of
the tested cards with short comments and links to the HD Tach diagrams
(without comments), and if you are interested in pure test results go to
the end of the review that gives three diagrams with the key results and
some comments.
Digitex
The 512 MB card differs marginally from its less sizable sibling. The
most peculiar difference is the lacking ® sign in the company's name on
the front side. They also behave differently in operation.
The Premium series is quite new. According to the company, it's for
those who need a higher speed than the Optimal can offer. However, there
are Optimal and Premium cards of the same size, though Premium cards greater
than 128 MB are not available yet. That is why it was curious to compare
Optimal and Premium cards of the same and different sizes.
Kingston
It's one of the leaders in manufacturing various memory types. Its products
often hit top marks in tests. And its cards come with a 5-year warranty
(memory modules come with the life-long warranty).
PQI
This grand has a little stained reputation. Its cards of the "G" series
sometimes accidentally got onto the retail market, and old flash card controllers
had a low speed (Q4 and Q5). However, we tested the cards with a new controller
(Q6) that performed brilliantly. At the same time, the PQI products are
rather cheap which makes them very attractive.
This is a new PQI on another controller. The speed is higher, but the
price is maintained the same, which makes the PQI Hi-Speed a bargain. "24X"
written on it implies speeds up to 3600 KB/s ("X" is the same as in CD-ROM)
but it doesn't specify whether it's for reading or recording.
While cards from other manufacturers allow users to make notes on the
back panels, the PQI cards have no space for them, which is a little unpleasant.
Ridata
Samsung
First the company dealt mostly with SmartMedia. Then it established
an agreement with Sony concerning MemoryStick. And now its attention was
arrested by CompactFlash.
There is no much space to leave notes on the rear panel.
Sandisk
This brand-name manufacturer on the flash card market provides a 5-year
warranty like Kingston. Let's see whether the performance correlates with
the price.
The Ultra series, like Digitex Premium or PQI Hi-Speed, was developed
for demanding users. Once we compared
the Ultra with usual cards from Sandisk, now it's time for a big contest.
Transcend
This is one more widely known manufacturer which states the 25X speed
without mentioning whether it's a reading or writing speed :))
Viking
This company is widely known in the USA, hence 160 MB, which looks an
exotic size.
Like PQI, it doesn't provide space for notes.
Test results and comments
Let's start with access time.
How do you like the Sandisk results? Well, we couldn't choose a diagram
scale to include these cards and make the others looking different from
zero. If we exclude these three cards the difference between the slowest
and fastest samples is 1.1 ms (it's almost a double difference), the fastest
Sandisk falls behind the local outsider by 30 ms! 15 times gap. Well, the
Sandisk is not a right solution to store large amounts of small files.
Fortunately, it's not crucial for photo equipment.
Almost everywhere the less sizable cards perform better, except the
Digitex Optimal 512 MB which is less sluggish than the 128 MB sample. The
Premium comes with decent scores - it shares the second position with one
of PQI and Viking cards outscoring the Optimal (only the Sandisk performs
worse which is beyond any comparison here), and the most cards from other
companies. The PQI Hi-Speed is 1.5 times slower than the Q6 - not all parameters
were improved.
Now the read speed.
The Samsung has unexpectedly saddled the top, and it's followed by the
Kingston, Ridata and Transcend which keep closely together (it's interesting
that the Transcend and the Ridata of the same size have equal read speed
and access time). The PQI Hi-Speed is close on the heels, and it lags from
the Samsung by just 6%.
The Sandisk gives way to the last position to the Digitex Optimal 128
MB (without this card the Sandisk would have none to compete against).
The Premium 128 MB is noticeably ahead of the Optimal of the equal size
and just a little behind the Optimal 512 MB. The Viking runs at almost
the same rate, PQI Q6 throttles back though it's still more powerful than
the outsiders.
Now the write speed scores.
The first thing that my eye catches is that 24-25X wasn't reached -
the leaders are limited by 20X. Secondly, the Samsung's fourth position
from the end is incomparable with the first one from the beginning in the
read speed test. The Ridata and Transcend come forth with almost equal
results. The Kingston's card is 20% slower than the champions. The Sandisk
Ultra gains the revenge - it takes the third position falling a little
behind the Kingston. Then come PQI Hi-Speed and Digitex Optimal 512 which
again outscores the Premium. The PQI Q6 gets the golden mean and the Viking
edges out the Samsung. The Sandisk, especially 512 MB, shows poor scores
again, as well as the Digitex Optimal 128 MB. If you return to the beginning
of the review you will see that the latest card falls behind even the aged
Transcend.
Summary
If speed is the most vital parameter for you go with the Transcend or Ridata:
the second position in reading and first (which is more important) in
recording. The Sandisk solutions are hardly a good choice even for photo
equipment (not to mention other area of application): the ordinary cards
failed in all tests, the Ultra is more successful but... There is Kingston
whose solutions are more efficient and less expensive with the same
warranty period. The middle positions at a moderate price are taken
by the Digitex (except the small-size Optimal, but they can be replaced
with Premium) and PQI Hi-Speed (the price gap between the HS and Q6
is inconsiderable, that is why the former looks more optimal). The Samsung
cards are a sound decision for those who shoot in JPEG (where a very
high speed is not crucial) and transfers photos into a computer using
high-speed interface. These cards are not too pricey. If the company
pulls up the write speed up to a couple of megabytes per second its
products will stand a chance to gain more popularity. As we can see,
this manufacturer is quite capable as it manages to take the palm in
the read speed test. As for the Viking and Samsung (or PQI), the latter
looks more touching.
That's all for today. When we get new results we will certainly publish
them and, probably, change the conclusion. But it's for you to make a choice
- thankfully - all the necessary data are provided.
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