By Comparison: MPEG-4 Three Times The Workload Of MPEG-1
The average value measured for a long video sequence is a very important number when testing CPU workload because MPEG-4 operates with variable compression and therefore a variable data rate. Therefore the CPU workload depends on the complexity of the respective scene. Fast movements require a higher data rate while scene with less changes are handled with much lower data rates.
The CPU workloads displayed are the average values measured with the previously mentioned four-minute MPEG-4 sequence. The software used for playback was the Divx software codec, which is basically a hacked variation of the Microsoft codec.
The CPU workload with MPEG-1 is about a third of that required for MPEG-4. However the image quality and resolution are much worse and no longer state-of-the-art.
The table above shows the CPU workload for MPEG-1 video. The load is only about 35 percent even with an old Pentium II/400. The fastest processor, AMD's Athlon 1100, is only loaded by 10 percent during playback.