Apple Final Cut Express HD - Manual (Page 870)

870 Part X Real Time and Rendering
About External Video Monitoring
If you enable DV output via FireWire, real-time playback is disabled.
Available Real-Time Effects
Video transitions and filters that can play back in real time appear in boldface type in
the Effects tab in the Browser and in the Effects menu. The following effects can play
back in real-time:
 Superimpositions: Simultaneously superimposed video clip items in the Timeline with
different opacity settings can be played back in real time. Your disk speed and the
processor speed of your computer together determine how many simultaneous
video streams can play back in real time
 Still frames: Still frames and imported graphics can also play back in real time. The
number of still images that play back in real time depends on the size of the Still
Cache set in the Memory & Cache tab of the System Settings window.
The size of the still cache is limited by the total amount of unused physical RAM
installed in your computer. The higher the still cache, the more stills that can be played
back in real time in the currently selected sequence. If another sequence is opened, the
contents of the still cache are automatically replaced with stills from the new sequence.
Maximizing Real-Time Playback Performance
Many aspects of a computer system contribute to the playback of real-time effects:
 CPU speed: The faster your computer CPU is, the more real-time effects
Final Cut Express HD can perform.
 Multiple processors: Computers with more than one processor have significant
real-time performance advantages over single-processor computers.
 Level 2 and Level 3 processor cache: The sizes of a computer processor’s level 2 and 3
caches affect its real-time capabilities. The larger these caches are, the more
real-time performance is available.
 RAM: The more RAM you have available in your computer, the more potential
real-time performance your computer has.
 Memory bus speed: Computers with a faster memory bus allow better real-time
performance.
 Fast hard disks: Faster hard disks improve real-time playback performance,
especially with multiple video tracks.
 Fast graphics card: OpenGL, a simple set of computer graphics subroutines that can
be built directly into a video graphics card, is used to accelerate real-time display in
the Viewer and Canvas.