This is a simple test that uses plain MS DV AVI type II PAL clips, without effects, transitions or modifications, exported in the same format. It uses nearly 1640 instances of the same clip, to be exported to one large AVI file. Because there is nothing modified at all, there is no MPE involvement.

All the work is done by the CPU, the memory and the disk(s).

Get the first clip instance from disk and store it in memory, get the next instance from disk and store it in memory, etc. This will fill up memory rapidly, so at a certain moment memory needs to be freed and written to disk. Then the next bunch of instances are handled and the process repeats itself. BTW, the multi-threading in this case is far from optimal, but is expected to be corrected in a future update.

The CPU has a relatively easy job. It is the supervisor that tells his subordinates (memory and disk(s)) what to do. In this case the disk(s) cause the waiting, because they are the slowest components in the chain. Memory is much faster and can easily keep up with the disk activity and MPE is out of a job on this task, sitting on the fence watching the other components work up a sweat.

What is the lesson to be derived:

  • The faster the disk(s) and the larger the disk cache, the better. This is an area where large Raid arrays show their advantage, especially if helped with large cache memory on the Raid controller.

Of course more cores and higher clock speed do help too, but not as much one would hope for.