Overclocking makes the biggest difference in iTunes, as the mid-priced system starts out only 22% ahead of the lower-cost configuration but leaps to a 66% advantage when tweaked. The high-priced gear starts out with an impressive 60% advantage and doubles its lead when overclocked.
Overclocking again plays a bigger role than hardware specifications in Lame performance, with the mid-priced system jumping from 44% to 98% over the lower-cost system, and the high-end configuration sliding from a 68% to a 144% lead.
TMPGEnc gets smaller boosts from overclocking, with a spread between the slowest and fastest configuration of "only" 89%. The smaller difference follows our previous observation that DivX encoding speed is limited by a greater number of factors including memory speed, whereas our memory overclocks were not nearly as large as those of our processors.
CloneDVD2 increases the spread between lowest and highest transcoding speeds to 101%.