PVRs are a relatively recent technology in the consumer electronics world, first appearing in 1998, and only a few models are available thus far. Several other companies have entered the PVR market in recent months. As the technology evolves, we'll revise our report accordingly. Reviewers differ about the image quality of PVRs. As with VCRs, PVRs record in three speed modes, which produce different levels of image quality.
Reviewers do seem to agree, though, that high speed produces DVD-quality images.
The problem, of course, is that high-quality images take up more memory, and when the PVR runs out of memory, it starts recording over previously recorded material. Models that tout a 30-hour memory have only 10 hours when used at the highest quality. Which scheduling approach is best depends on your own preferences for control versus simplicity. Simpler systems require that you give up some control, while systems that offer more control are also more complicated. All PVRs eliminate previously recorded shows to make room for newly requested shows.