The number of different formats available in DVD drives can be confusing
to anyone in the market for one. The list is much longer, but to
address a few of the common formats, we have DVD-ROM, DVD-R, DVD-RW,
DVD+R, DVD+RW, DVD-RAM ,DVD+R DL and DVD±RW. Wow! This list of common
formats is long enough, no wonder it’s confusing!
What’s with all the Formats?!
The reason for various recordable DVD formats is that no one group owns
the technology and different Groups have chosen to support one
technology over another. There is no industrial standard for
manufacturers to reference, so for the time being consumers will have a
few choices.
The first thing to address is DVD itself, which stands for Digital
Versatile Disc. Some may argue that the V stands for Video, but with the
capability to store video, audio, and data files, Versatile is
definitely the keyword.
Start with the Basics
A DVD-ROM drive is the only one we will address that does not record.
ROM stands for Read Only Memory, and refers to the typical drive that
can merely read DVDs, as well as CDs (all DVD drives can read CDs). The
Lite-On LTD-163-DO-R has attributes representative of your typical
DVD-ROM drive, and features a maximum DVD read speed of 16x and a
maximum CD read speed of 48x.Before getting into the different
recordable formats, let’s address the basics of what the R and RW stand
for, regardless of whether there is a + or – in the middle. R stands for
Recordable, which indicates that the disk may be recorded to only once.
RW stands for ReWritable, which indicates that the disc may be recorded
to more than once, and are generally rated for 1000 rewrites under good
conditions.
The DVD-R/-RW format was developed by Pioneer, and was the first format
compatible with stand alone DVD players. The group that promotes the
technology calls itself the DVD Forum, which is “an international
association of hardware manufacturers, software firms, content
providers, and other users” with notable members such as Hitachi,
Samsung, and Toshiba. The DVD-R/-RW format is based on CD-RW technology
and uses a similar approach to burning discs.
The DVD+R/+RW format is a newer format, also based on CD-RW technology,
and compatible with a large percentage of stand alone DVD players. The
+R/+RW technology is not supported by the DVD Forum, and its main
backing comes from a group called the DVD+RW Alliance. The Alliance “is a
voluntary group of industry-leading personal computing manufacturers,
optical storage and electronics manufacturers” with members such as
Dell, Hewlett Packard, Sony, and Phillips Electronics.
The DVD-RAM format is based on PD-RW (Phase-Differential) drives, and
actually uses a cartridge to hold the media (just like its PD-RW
predecessor). Some DVD-RAM cartridges are double sided, making them
ideal for companies to use as system backup, hence DVD-RAM is usually
found only in commercial applications, and most end-users won’t ever
need to use or see this type of drive. The DVD-RAM standard is also
supported by the DVD Forum just like the DVD-R/RW format. However,
because of its use of a cartridge (limiting it’s compatibility), and the
scarcity and price of the media used, DVD-RAM is a distant third when
compared to the DVD+R/+RW and DVD-R/–RW technology.
The +R/+RW and –R/-RW formats are similar, and the main difference DVD+R
technology has is the ability to record to multiple layers (with its
new DVD+R DL format), where DVD-R can only record to one layer (not all
+R drives are capable of dual layer burning, but no -R drives are). The
Plextor PX-504U is an example of an external DVD+R/+RW drive capable of
recording single layer discs in the +R/+RW format, but also able to read
discs recorded by a DVD-R drive.
What is DVD±RW?
DVD±RW is not actually a separate format, but the designation given to
drives capable of both –R/–RW and +R/+RW operation. This type of drive
is typically called a “Dual Drive” (not to be confused with a “Double
Layer” drive) since it can write to both the +R/+RW and –R/–RW formats.
The Samsung TS-H552 is a DVD±RW drive capable of reading and writing
every format discussed so far, and then some. It takes advantage of
DVD+R DL (Double Layer) technology available with the +R format,
allowing the appropriate media to store virtually double the 4.37 GB
capacity of a typical single layer disc.
The other main thing to consider with DVD burners is selecting the
correct media. Media for DVD-R, DVD-RW, DVD+R and DVD+RW media may all
look the same, but they are slightly different in order to match the
specific recording formats. The price of media for either format is
generally the same, with RW media costing a good deal more than R media
of either format. Double Layer media is even more expensive, and is the
only way for an owner of DVD+R DL drive to take advantage of the
tremendous capacity increase. As the amount of Double Layer drives
increase in the market, the price of the DVD+R DL media is expected to
fall with increased production of the media. DVD Burners (as these drive
are often referred to) can be picky about the media supported, so be
sure to choose your media wisely.
DVD in a Nutshell
DVD-ROM : Reads DVD discs
DVD+R : Writes to DVD+R media (will also typically write to CD-R and CD-RW media)
DVD+RW : Writes to DVD+RW media (will also typically write to DVD+R, CD-R and CD-RW media)
DVD+R DL : Writes to DVD+R DL (Double Layer) media (will also
typically write to DVD+R, DVD+RW, CD-R and CD-RW media; many Double
Layer drives are ALSO dual drives – that is, able to write to BOTH +R/RW
and –R/RW media)
DVD-RAM : Writes to DVD-RAM cartridges (not in wide use on consumer
market – mainly a business format; can also read PD-RW discs. Will not
usually be able to write to any other format including CD-R or CD-RW)
DVD-R : Writes to DVD-R media (will also typically write to CD-R and CD-RW media)
DVD-RW : Writes to DVD-RW media (will also typically write to DVD-R, CD-R and CD-RW media)
DVD±RW : Writes to DVD-RW and DVD+RW media (will also typically
write to DVD-R, DVD+R, CD-R and CD-RW media; typically called “Dual
Drives” since it can burn to two different DVD formats)
Final Words
This article took a look at the more common formats of DVD drives in
order to shed some light on all the choices available. The differences
between them all may be subtle, but the compatibility issues can be
quite frustrating. The simple answer to anyone considering a drive is to
forget about + and – by themselves, and shoot for universal
compatibility with a good DVD±RW with DVD+R DL support.
Tags: <Computers, DVD Drives>
Choosing a Computer Case
December 23, 2004 • Posted in Computers • Comment
In the past, computer cases were all very similar. Clones of the same
boring, beige box. With all of the choices available today, this is no
longer the ‘case’, and people can use their systems’ chassis as a means
to express themselves and to set their system apart from the rest.
Although appearance may be a big one, it isn’t the only factor in the
selection process and the following items should be considered when
shopping for a new computer case.
1. Form Factor
There are different sizes of motherboards, which in turn require
different cases to house them. Case form factors share the names of the
motherboards they support, and some of the common ones include ATX,
Micro ATX (mATX), FlexATX and Mini ITX. ATX motherboards are perhaps
the most common, and the largest of the four, measuring at most 12″ x
9.6″ (305mm x 244mm). A Micro ATX board is at most 9.6″ x 9.6″ (244mm x
244mm), a FlexATX is 9.0″ x 7.5″ (229mm x 191mm) and a Mini ITX comes
in at a tiny 6.7″ x 6.7″ (170mm x 170mm). ATX and mATX are by far the
most popular motherboard sizes for consumer motherboards, and hence,
most cases are made to support one or both of these sizes.A mATX
motherboard can obviously fit in a smaller enclosure than an ATX
motherboard, and therefore there are different size cases available to
match. The larger cases are generally downward compatible with smaller
form factor motherboards, but the opposite is not true. For example,
someone with this Amptron mATX motherboard could save a few inches and
install it in this14.25″ tall mATX case, or pick something like this
black ATX case that stands just a bit taller at 16.5″.Many branded
systems (ones that you may buy prebuilt and with preinstalled software)
are usually a combination of a standard form factor (such a mATX) with
some type of proprietary design (usually in the front panel switches and
cabling) and buying a new case for these types of motherboards can be
tricky. Some branded systems also use lesser used form factors such as
NLX and LPX (which employ riser cards for the expansion slots) and
finding replacement cases for these type of systems can be a very
difficult and pricey endeavor.
A smaller system may be desirable where space is tight, but larger form
factor cases provide more room for multiple drives and other
peripherals, and a smaller motherboard may be better suited to a larger
case in a system such as this.
2. Size
Size may go along with form factor in many respects, but even while
considering cases of the same form factor, there can be variations in
size in a few respects. Areas where size can vary are in overall
dimensions, the number of exposed 5.25″ and 3.5″ bays, and the number of
internal bays.ATX cases obviously need to be large enough to hold an
ATX motherboard; some are just large enough, while others seem cavernous
in comparison. If a case needs to fit under a low shelf, or between
items of a certain width, it is important to choose an appropriately
sized case. Cases come in two basic configurations when it comes to
their size and shape, either desktop or tower. Desktop cases are wider
than they are tall and are oriented so the motherboard lays flat, while
tower cases have the motherboard standing upright, and come in three
basic heights. mini tower, mid tower, and full tower.The number of
exposed drive bays is generally in direct proportion to the overall size
of the case. A higher number of exposed 5.25″ bays may be desirable for
those with more than one DVD or CD drive, removable drive racks, and
fan controllers. Exposed 3.5″ bays are generally occupied by floppy
drives, Zip drives, fan controllers, and things like this 9-in-1 Card
Reader, and in most cases you may get one or two of these bays,
maximum. This case is very similar in appearance to this other one, but
they have one difference that may prove to be a huge factor. They both
have four exposed 5.25″ bays, but one has two exposed 3.5″ bays while
the other only has one. If a user had a floppy drive and the 9-in-1
card reader, they would either have to choose to install only one, or
use an adaptor and take up one of their 5.25″ bays.
Internal bays are generally reserved for hard drives, and systems with multiple drives require the necessary space.
3. Cooling
Cooling is a critical feature to consider when selecting a computer
case. High end systems can generate a good deal of heat, and the case
needs to be adequately cooled to keep the system running and stable.
The basic configuration for case cooling involves having one intake fan
on the lower portion of the front surface, and one exhaust fan higher up
on the rear surface. This allows cooler air to be drawn in, passed
over the various heat generating components, and exhausted out the
back. There are many other cooling configurations available that may
provide improvements in terms of cooling performance and noise.
One way to decrease noise, and perhaps move more air, is for a case to
use 120mm (4″) fans instead of the usual 80mm (3″) fans, as larger fans
don’t need to spin as fast to push the same volume of air. This A-Top
Z-Alien utilizes a 120mm exhaust fan that also features another key
feature to good cooling. The fan grill is very open, meaning that there
will be minimal resistance to air flow and reduced noise as the air
rushes past it. Many fan grills are made from perforating the case’s
sheet metal, and they do not provide enough open area for good airflow.
Another approach to better cooling is to throw more fans at the heat.
This Matrix case adds another fan to the side panel which will draw cool
air in right on top of the processor and video card, two of the hotter
items in a system. Other cases will add an exhaust fan to the top of
the case, which pushes the heat out just like a chimney.
No matter the approach, cooling is one area that needs close
consideration when it comes to cases intended for today’s high powered
systems.
4. Installation Features
Installing a system into a case can be a time consuming affair, which
can become annoying to those who find themselves in a continuous cycle
of upgrading. Many cases now include convenient features to make
installation much simpler, and far less time consuming
Some of these convenient installation features include a removable
motherboard tray, removable drive cages, tool-less expansion card
mounts, tool-less side panels, and tool-less drive rail systems. Being
able to remove the motherboard tray and drive cage makes it easier to
work on those specific areas in the open, and having a tool-less system
for mounting drives or cards means there is no need for screws or a
screw driver. Definitely time savers!
Although the listing on the Computer Geeks site does not specify it,
this X-Blade ATX case features both a removable drive cage and tool-less
drive rail system, according to this review.
5. Convenience Items
It is not enough for a case to house a computer system any more, it now
needs to multi-task. Having regularly used connections on the front or
top of the case is one common convenience feature that many people look
for. Cases such as this A-Top Z-Alien model let users forget about the
annoyance of reaching around the back of their case to plug things in,
as USB, Firewire, headphone and microphone jacks are located on the top.
Other cases are available that take convenience to another level by
including clocks, digital thermometers that monitor specific components,
and fan controllers to help maintain a healthy balance between noise
and cooling performance.
6. Style
A few years ago cases only came in one color and one basic style. plain
beige boxes. If you’re nostalgic for the olden days of computer cases,
Computer Geeks still has one for sale in this style, the KG-200. But
cases now come in styles from mild to wild, and in a whole rainbow of
colors. Some have large windows in the side panel to show off the
case’s insides, some include special lighting effects, and some have
appearances that might scare the kids. At this point there seems to be
few limits in case design, but there are always classically styled cases
in updated color schemes for those who want something modern looking,
but nothing too intense.
7. Power Supply
Many cases are sold with a power supply included, but this power supply
might not be the correct one for the system to be installed inside of
it. An adequate power supply needs to be chosen to meet the demands of
the system, and this may very well mean buying an additional power
supply to replace the one included, or selecting a different case with a
more appropriately sized power supply.For example, someone may decide
their high end gaming system would go well in this black ATX case, but
the included 300W power supply may not be strong enough for a top notch
graphics card, multiple drives, water cooling, and other power hungry
peripherals that might be installed.
Final Words
There are many factors that go into selecting an adequate case for a
computer system, including the seven mentioned above. What may wind up
being the most important factor was not discussed, but can hopefully be
addressed by balancing the importance of these factors. price. Computer
cases can cost anywhere from several dollars to several hundred
dollars, meaning that a tight budget may decide which of the other
features is really all that important.
