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Hard disk

The second most common problem is slow hard disks. Until recently, fast, expensive SCSI AV hard disks were required to properly capture and play back video on a PC. Slow hard disk problems also manifest themselves with jerky video playback, although the stutters are less frequent and of longer duration than if the video subsystem is the problem. Slower hard disks (e.g., 5400 RPM IDE) can cause an occasional dropped frame. DV enthusiasts have fewer problems due to the low data rate (~3.6 MB/sec.) of that format. The following section outlines some recommendations arranged in order of importance.

Buy a dedicated video drive. This is easily the most important piece of hardware advice. A dedicated, physically distinct hard drive is almost a requirement for any type of serious video work. This means that you have one primary C:\ drive (or wherever your operating system is installed) and a separate drive for video. You can use your dedicated drive for other purposes, especially storage, but it is a good idea not to run any applications from it and to keep Windows virtual memory off of it. It is very important that the drive only be used for video when playing and capturing, and that other programs (including Windows) are not trying to access it. Since video files are so large, a dedicated drive is not an unreasonable item even if digital video is just a hobby. You can never have too much hard disk space.

Buy a faster hard drive. Older 5400 RPM hard drives may not be fast enough for capturing and playing back video for any length of time, while newer 7200 RPM drives are almost always adequate. Be careful: manufacturers are usually talking about burst transfer rates when they talk about the speed of a drive. A drive that can transfer data at 80MB/sec is worthless for video if it cannot sustain a much slower rate of 8MB/sec for thirty minutes (or more) without dropping a frame. Look to other computer video enthusiasts for additional advice. Again, the RPMs are a very good indicator, because 7200 RPM IDE drives are usually newer (c.1998) and older 7200 RPM drives are usually SCSI, which are already higher quality drives to begin with.

IDE vs. SCSI. While this was a big issue just a few years ago, it has fortunately faded in importance. Hard drives can be hooked up to your computer in a number of ways, with the two largest divisions being IDE and SCSI. This interface simply determines how much data can be transferred to and from the drive in a second. The interface almost always far outstrips the performance of even the best hard disks and even the slower interfaces exceed the transfer requirements of video data. SCSI hard disks are usually more expensive and require a special controller, and while SCSI-2 promises 80MB/sec transfer rates, this is overkill for most people. Newer IDE hard disks with designations of EIDE, DMA, Ultra-DMA, ATA-33, and ATA-66 (and newer drives that came out after this writing) can all handle most sustained video requirements.

CPU and RAM (memory)

While the CPU and the RAM are probably the most important overall aspects of a PC’s speed and performance, these factors are only third on the list for video. For the most part, these critical components do not affect the capture or playback of video. This does not mean that a faster CPU or more RAM will not help, because bigger and faster is always better: CPU and RAM definitely impact rendering speeds. Creating a final AVI file, especially in a movie project that uses a lot of effects and transitions, can take a long time. A thirty-minute movie could easily take six or more hours to render, depending on the format and effects used. CPU speed is also important for more advanced compression codecs, such as MPEG and newer streaming formats.

TROUBLESHOOTING

APPENDIX A