DVD Drives

Welcome to the exciting world of DVD technology! DVD, an acronym for Digital Versatile Disc (originally Digital Video Disc) is the newest technology in home entertainment. Although physically identical in size, each DVD disc can store anywhere from 4.7GB-17GB (gigabytes) of data per disc. That's 12 times more data than CDs, which max out at 740MB (megabytes) per disc. In addition, DVD drives have much higher data transfer rates than CD-ROM drives. So, it's no wonder DVD provides better picture and sound quality than CD's, VHS tapes, and laser discs.

DVD uses MPEG-2 video and audio compression, which produces crisp, sharp images, and offers the option of Dolby Digital and DTS (Dolby Theater Systems) sound. MPEG-2 delivers 480 horizontal lines per frame, compared to 425 for laser discs, and 250-270 for VHS.

Another benefit of DVD drives is their ability to support multiple media types such as CD-ROMs, CD-Rs, CD-RWs, photo CDs, audio CDs, and the list goes on. That's right--you can play Santana's latest in your DVD drive while surfing the Internet.


System Requirements

The following is a list of features your system must have in order to support a DVD-ROM drive. Luckily, most individuals shouldn't have any trouble meeting these requirements.

Pentium II 300 or higher (Note: if you are running a powerful enough CPU, you may not need the assistance of either a hardware or software-based decoder.
At least 32MB of RAM (64MB RAM recommended)
One open 5.25" drive bay (A drive bay is not necessary if you are planning on purchasing an external DVD drive, but the price will be substantially higher. You will also need a USB port, FireWire port, or a SCSI port available to plug in the external DVD drive.)
One PCI slot available for a hardware-based decoder card (A PCI slot is not necessary if you are using software-based decoding.)
An 8MB 2D video card is recommended, but as long as it supports 16 bit color, you should be okay. You'll need to make sure your video card is compatible with the DVD drive you select. (Note: if you are running a powerful enough video card, you may not need the assistance of either a hardware or software-based decoder.)
Basic sound card (One with a digital output is needed if you want to take advantage of multi-channel digital sound. In addition, you will need to make sure your sound card is compatible with the DVD drive you select.)
Multimedia speakers
Hard drive space (Ample hard drive space is needed if you are considering purchasing a DVD-ROM drive that utilizes "software-based" encoding which requires you to install certain software programs.)
Windows 95/98/NT 4.0/2000/ME



Speed and Performance
The speed of DVD drive you ought to look for depends on your needs; however 8X (8 speed) or higher is recommended. Although 8X may sound slow compared to a 52X CD-ROM, it really isn't. The data on a DVD disc is packed tightly together, which allows for much faster data transfer/access rates than those of CD-ROM drives. A 1X DVD drive can transfer data at 1,250KB per second, which is equivalent to the transfer rate of an 8X CD-ROM.

Access time, seek time, and buffer size also play an important role in determining the speed of a DVD drive. Similarly to CD-ROM drives, the lower the seek and access times, the quicker the drive retrieves and reads data. The standard buffer size for most DVD drives is 256KB; anything greater is a plus.


Interface Options
The speed of a DVD drive also depends on which interface you choose. A DVD drive's interface is basically the data pathway that connects the drive to your system's main memory. The main memory is the holding ground where the CPU retrieves data and instructions necessary to perform operations for devices such as DVD, CD-RW, or hard drives.

The two interface choices for internal DVD drives are EIDE (Enhanced Integrated Drive Electronics) and SCSI (Small Computer Systems Interface). EIDE is the more mainstream interface. For one thing, most motherboards come pre-equipped with EIDE connectors. In addition, EIDE drives are less expensive, and usually easier to configure.

On the other hand, SCSI is the more technologically advanced interface, and offers higher data transfer rates than EIDE. However, unless your motherboard already has support for SCSI hardware, you will need to purchase a SCSI adapter card, cable, and terminator.

For more on the differences between SCSI and EIDE, please see the GG Buyer's Guide: Hard Drives "EIDE/SCSI Comparison Chart."



Decoders
The data on a DVD disc is compressed and encoded into MPEG-2 format to minimize the space it occupies on the DVD disc. Therefore, in order to use that information it must be decoded. Most CPU's and Video cards that came to market after 1998 are powerful enough to decode MPEG-2 themselves. However, performance will be better if you have a decoder. There are two types to choose from--hardware-based and software-based.

Hardware-based decoders are recommended for computer systems running on Pentium II 300's and below because they minimize the strain on your CPU, while optimizing DVD performance. In addition, if you plan on running multiple applications at the same time, a hardware-based decoder will offer superior performance.

Software-based decoders are recommended if you are running a fairly fast CPU, or don't have a PCI slot available for a hardware-based decoder card.



Regional Codes
Since movies are released at different times in different countries, motion picture studios began requiring the implementation of regional codes. Each DVD player is given a specific code so that it may only play DVD movies of the same code. In other words, a DVD player in another country may not recognize movies released in the US.

Although this minimized bootlegging, it soon became quite complicated as it was nearly impossible to include codes for every region. This was primarily due to the plethora of spoken languages, as well as censorship laws. As a result, many companies began configuring their DVD players to play discs from all six regions. If a DVD drive is capable of this, it should be indicated in the drive's specifications.



Conclusion
DVD drives are on their way to replacing CD-ROM drives altogether. Already, much educational and reference material is being produced for DVD. DVD media's huge capacity makes it possible for publishers to include more images, audio, and video clips in their software, which helps to enhance learning and understanding.

There are numerous advantages to DVD movies as well. Again, the spaciousness of DVD media provides room for extras such as interviews with the director and cast, behind the scenes making of the movie, bonus footage, and songs from the film's soundtrack. In addition, DVDs frequently offer users the option of watching in alternative languages, which is a great way to work on your foreign languages skills!

Congratulations! You are ready to shop for a DVD drive. If you need extra help installing your new drive, CNET.com has a step by step installation guide in their "Help and How-Tos" department.