Most contemporary video codecs support multi-threading. Therefore, the use of dual-processor workstations may be theoretically justified for video encoding tasks. But what do the tests suggest in this respect:
The situation in popular codecs looks very similar to what we have just seen in ScienceMark. And the reasons are about the same. Not so long ago codec developers managed to optimize their products for systems capable of performing two computational threads simultaneously, and we are asking for the four-processor support already… Unfortunately, most codecs are still incapable of loading four processor cores with sufficient amount of work.
At the same time I would like to point out that the title of the fastest system for video content encoding has been won by the dual-Opteron 254 system. Besides processing two computational threads at the same time, it is also built with two fastest CPUs working at 2.8GHz frequency, which are analogs of the desktop AMD Athlon 64 FX-57.
However, some steps towards better optimization of the codecs for multi-processor platforms are still being made. For example, last week a new DiVX version 6.1 came out. Besides some other improvements it promises to deliver higher performance in multi-threaded environments. Unfortunately, DiVX 6.1 appeared incompatible with the current AutoGK interface version, so we couldn’t run the tests the usual way this time. So, in order to include this codec into our today’s test session we resorted to the VirtualDub utility. Unfortunately, we will not be able to compare the performance of the old and the new codec, but we can still get some idea of the platforms’ relative performance when using DiVX 6.1 codec.
According to the diagram above, a lot has changed. Now we have every right to say that DiVX 6.1 works very efficiently not only in systems with two logical processors, but also in systems with four logical processors. In particular, now the system built with two dual-core Opterons runs faster than all Xeon platforms as well as a single-core Opteron 254 platform. As for the dual-core Xeon processors, they are again demonstrating pretty bad results. Their ability to process 8 computational threads at a time cannot make up for the low clock frequency.