Adobe PREMIERE 5 User Manual page 368

360 APPENDIX C
Maximizing Performance
Hardware compression on the video-capture card can greatly increase performance and
reliability by reducing the amount of data that the card passes on to the rest of the system.
Video cards that have Motion JPEG compression can usually capture full-motion video effec-
tively. To determine what settings will produce the best results for your projects, see "Under-
standing scenarios that affect compression" on page 347 and the documentation provided by
the manufacturer of your video-capture card.
Hard disk
The hard disk must be fast enough to store captured video frames as quickly as they arrive
from the video card. If the hard drive cannot keep up with the incoming frames, frames will
be dropped from the captured clip. For capturing at the NTSC video standard of 30 frames per
second, your hard disk should have an average (not minimum) access time of 10 milliseconds
(ms) or less, and a sustained (not peak) data transfer rate of at least 3 MB per second but
preferably around 6 MB per second. (The access time is how fast a hard disk can reach specific
data located anywhere on the hard disk. The data transfer rate is the volume of data that moves
between the hard disk and other system components.) As a general rule, the actual video-
capture data transfer rate will be about half the data transfer rate of the drive, after accounting
for overhead and other factors. Use the following guidelines when capturing to a hard disk:
Use an AV (audio-video)-certified high-speed hard disk. AV hard disks are specially designed
•
to sustain very high data rates for a sufficiently long duration to capture video without
dropping frames. If you have more than one hard disk, capture to your fastest AV hard disk.
Use an AV hard disk controller, such as Fast SCSI-2 card.
•
Use a separate hard disk or create a separate partition on your hard disk for capturing video.
•
If you create a separate hard disk or partition for capturing on your hard disk, use Premiere's
Scratch Disks preferences to select the disk or partition to which you want to record. See
"Setting up Premiere's scratch disks" on page 71.
Keep the capture disk defragmented so that the free space is available in large contiguous
•
blocks. A fragmented hard disk can reduce the frame rate at which clips are captured. Use a
defragmenting utility as often as necessary.