In the mid-1990s, when the low-cost digital video editing revolution was just beginning, the typical computer was a Pentium 100 with 16 Megs of RAM, a 4 Gig Ultra-SCSI A/V drive and a miro (remember them?) capture card. Between system crashes, lack of disk space and long rendering times, editing was tedious.

Today computers are 20-times faster and memory is dirt cheap and capture cards are more efficient and less expensive.

In order to understand how PC computer-based editing systems work, let's take a look at each component. The "brain" of a computer is the CPU (Central Processing Unit).When editing video, faster processors will take less time computing elaborate transitions or the layering of text and video. It is important to have an adequate amount of RAM (memory), which gives the computer plenty of breathing room. 512 Megs of RAM or more is recommended.

The hard drive is crucial in a video editing system. A separate drive should be used solely to store video information. This drive should spin at 7,200 RPM and should have an ATA-100 transfer rate. Even better, some drives spin at 10,000 RPM and have an ATA-133 data transfer rate. These are standard, off-the-shelf drives and are very inexpensive. Since video tends to eat up drive space very quickly, it is recommended to buy the biggest drive you can afford.

The motherboard accommodates all of these components and helps them communicate with each other. Since the hard drives communicate at 100 or 133 MHz, the motherboard must also be able to communicate at this level. Therefore, it is necessary for the motherboard to have a hard drive controller that matches the speed of the hard drive. The bus speed of the motherboard is also an important factor, which is the speed that the components communicate with each other. Your computer has not lived until it has been asked to edit video. In this case, bigger is better.

The heart of a video editing system is the capture card. This is the interface between the camera and the computer. The most common way of transferring video is through FireWire (also known as IEEE-1394 and iLink). This is a special cable and connector that allows two-way transferring of digital video. The video is kept in the digital realm at all times using FireWire. The majority of capture cards on the market today use the FireWire method and many new computers are equipped with FireWire connectors right out of the box. In order to capture video using FireWire, the camcorder must have a FireWire connector. Some capture cards also include standard analog connectors for capturing footage from sources without FireWire, such as a VCR or analog camcorder. This type of card offers the most flexibility.

Once the footage is captured or transferred into the computer, it is ready for editing. With many cards, transitions and layering require rendering. Any time two elements need to be combined, the computer will "chew" on each frame to merge them. Faster processors will render these effects more quickly. There are several cards available that will do these tasks in real-time. Rather than having to wait for transitions and text layers to be rendered, they are available for viewing immediately. I reviewed two of these real-time capture cards and found the results to be remarkable.

In the following series of reviews (see issue article index), I tested two new NLE cards on a computer equipped with an AMD Athlon 1 GHz CPU, ASUS A-7v motherboard, 512 MB of RAM, and two ATA-100 Western Digital hard drives. Our computer was running the Windows XP operating system.