Power Up Your PC: Configuring the PC for Digital Video Editing (page 2)
Permanent Storage
One of the most important components in any digital editing PC is the hard drive (or hard drive system). It's the digital storage tank and all the video and audio data in any digital production ultimately must find its way on and off a hard drive. If the drive or its controller isn't able to move video data quickly enough, you'll be guaranteed uneven playback. More important than access time (how quickly the drive can get to and begin reading a specific chunk of data) is sustained data transfer rate.
Many drives perform well when asked to read or write just a small chunk of data. Ask a drive to move a lot of data over the course of several seconds (or minutes), which is what's required for video editing and playback, and the performance may not be so stellar. A drive's sustained data transfer rate measures how much data it can transfer continuously, which is critical for smooth digital video editing.
Today, there are three main types of hard drive/controller combinations you can buy. The older and less expensive IDE (Integrated Drive Electronics) standard has served well for a long time. This has been upgraded to the much-improved Ultra DMA/33 (Direct Memory Access), which approaches speeds necessary for hobbyist-level nonlinear editing. The newer SCSI (Small Computer System Interface) standard costs a bit more, but can offer the best overall performance.
Though many people equate SCSI interfaces and drives with faster data transfers, those four letters alone aren't responsible for drive performance. Instead of interface type, the primary factor in hard drive performance is drive RPM. The faster a drive is spinning, the faster it can access data and pass it to the controller. Drives turning at 7,200 RPM or higher are a must when working with higher data rates and better video quality. But faster drives also run hotter, and thermal recalibration--when the drive takes a brief break to adjust for changing temperatures--can interrupt the data transfer. This leaves blank spots and other anomalies that are definite no-nos for digital video.
Audio/Video (A/V) drives offer the added benefit of not performing this step while in the middle of a crucial file transfer. This isn't to say that you must use A/V drives for video editing, but you may experience occasional breaks in playback for no apparent reason if you don't. Countless thousands of people edit lower data rate video with standard, non-A/V drives every day, however, and relatively few have problems.
As with RAM, hard drive prices are experiencing a free fall. A/V drives are cheaper than ever, and most will keep up with the performance demands of home videographers. If you're picking one out, you probably want to start with a SCSI A/V drive in the 4GB range. If you can afford it, you'll never regret purchasing a drive with twice this capacity (or more). When it comes to video editing, you just can't have too much disk space. SCSI devices require that your PC have a SCSI port. If it doesn't, a SCSI card that fits into a slot on the motherboard can give the machine this capacity.
Video Capture Card
The video capture card is a critical piece of hardware for video editing. It typically doesn't come with a stock PC, but a digital video editing system must have one. It, too, plugs into a slot on the motherboard. The capture card has video in and out jacks to take the analog images from the camcorder tape and "digitize" them, which turns the images from analog into digital 1s and 0s. It then compresses the data it so it fits in a reasonable amount of space and sends it to the hard drive for storage. If you are using a DV format camcorder, where the video is already digital, then the capture card transfers the data straight from the DV tape to the hard drive. The format the card uses to compress the video (called a "codec," which is short for compressor/decompressor) is one of the key elements that establishes the cost of the card and the finished quality of the video. Other things to look for include maximum capture resolution (640x480 is the minimum necessary for high quality full-screen output to videotape), 60-field-per-second capture, and maximum color bit depth (24-bit being the standard for high quality color reproduction).
Consumer-level video capture cards run the gamut in price from about $150 for the least expensive to $5,000 for the most expensive (for more details, refer to Videomaker's Video Capture Boards Buyer's Guide, March 1998). Typically, the more money you pay, the larger the image and the greater the number of frames per second you can capture, edit and output to finished tape. Cards that create smooth, full-motion 30-frame-per-second video cost in the range of $350-$5000.
The Other Video Card
Not to be confused with the video capture card, the computer's "display adapter" is the video card responsible for creating what you see on your computer's monitor. In the grand scheme, this video card is rarely a source of bottlenecks leading to dropped frames. What it can do, however, is make for very sluggish screen redraws. A fast display adapter that supports high screen resolutions of 1024x768 or higher is preferred for editing video, as are color modes that will display thousands or millions of colors. Higher graphics resolutions virtually require a 17-inch or larger monitor as well. If you plan on spending much time in front of your editing system, you'll find that a large monitor is very helpful.
Set It Up
If setting up a PC for video seems like an insurmountable task, take heart. There are lots of available resources to help you, including this magazine, Videomaker.com, Internet Usenet groups, online help files and other knowledgeable PC users. There's also the option of purchasing a turnkey (pre-configured) nonlinear system, or having a computer vendor set up a system for you. Whether or not you build your own system, however, taking the time to really learn what's going on inside your video-capable PC will help you understand how to fix it when it breaks down. And that's information any PC-based nonlinear editor can use.
