How It Works: DVD

Coming Soon to a PC Near You

DVD's time has come--almost. According to analysts at International Data Corporation, DVD-ROM drives are expected to overtake CD-ROM drives as standard equipment on home and notebook PCs by 2001. But in the meantime, CD-ROM drives are still expected to outsell DVD-ROM drives 105 million to 22 million this year.

DVD-ROM drives fit into the same PC drive bays as CD-ROM drives. They have been optional in new PCs from just about every PC maker for the past year. Vendors including Hi-Val, Philips, and Sony sell external models; kits that include software and hardware decoders for MPEG-2 video run about $200 to $300. In 1999 PC makers started shipping more notebook computers with DVD-ROM drives, as fixed or removable devices. You can also buy third-party drives for notebooks that connect through the PC Card slot.

DVD-ROM drive read speeds--or "X" speeds--differ from those of CD-ROM drives. A first-generation 1X DVD-ROM drive reads discs at about 1.3MB per second and reads CD-ROMs at roughly the same speed as an 8X or 9X CD-ROM drive. The 4X and faster DVD-ROM drives commonly sold today read CD-ROMs at about the same speed as a 32X CD-ROM drive. Because of the paucity of DVD-ROM apps, the biggest benefit of buying a faster DVD-ROM drive is better CD-ROM performance.

If you have a processor slower than 300 MHz, you may want to get an MPEG-2 decoder card to watch DVD movies and run multimedia apps. Video is stored on DVDs with MPEG-2 compression. For the video to run, the data must be decoded, which requires lots of processing power; too little can mean dropped frames. An MPEG-2 card, which sells for $25 to $50, takes over the decoding work for the processor, allowing the video to play smoothly.

MPEG-2 decoders also typically offer a TV-out connector, which lets you watch DVD movies on a TV. Some new PCs include these decoder cards, while others include a TV connection jack on their video cards. If you want to watch full-screen movies on an underpowered notebook equipped with a DVD-ROM drive, you might need a PC Card MPEG-2 decoder like Margi's DVD-to-Go.

While DVD-ROM drives are positioned to replace CD-ROM drives, recordable DVD faces a stiff challenge from recordable CD formats, especially CD-RW. Drive vendors have divided into four camps, each supporting one of the four standards for recordable DVD. DVD-R hardware is sold exclusively by Pioneer, and the drives cost about $5000; DVD-R blanks, made by Pioneer and TDK, cost about $45 a pop. DVD-RAM drives from Panasonic, Toshiba, and Hitachi cost $300 to $700 and the discs sell for $25 each. DVD-RW drives from Pioneer have appeared only as consumer-electronics devices costing about $2400, with discs running $30. Finally, Sony, HP, Yamaha, and Philips back DVD+RW but haven't yet released products.

At the moment, DVD-RAM is leading the recordable race. However, only users who need storage with extremely high capacity are turning to it. Most consumers who need optical storage find that CD-RW drives fit their needs much more affordably. According to IDC analysts, recordable DVD drive sales won't pick up until more drives capable of reading recordable DVDs hit the market.

Additional Resources:

• DVD Forum
  
  
• The DVD FAQ
  
  
• A Closer Look at DVD