QTPC 05 - 68030 vs. 68040 Memory Allocation (1-Aug-95)
Q QuickTime apparently allocates free memory during movie playback on 68030 CPUs,
but not on 68040 CPUs. We tested this on Performas, a IIvx, and a IIcx. When we
run the same test on Quadra 700, 800, 840AV, and Centris 650 Macs, the amount
of memory used remains more or less the same during playback. Is QuickTime
doing some special CPU handling to improve playback performance on slower Macs
(68030s vs. 68040s)?
A Since the 68030-based Macintoshes are significantly slower in operation than
those based on the 68040, they require a larger cache size to play back movie
files at their optimal settings. QuickTime attempts to compensate for the
reduced system performance of these slower machines by storing as much of the
movie file as possible in memory.
