Six-Core Analysis, Part 2: Intel Core i7-980X Scaling

Intel's Turbo Boost technology provides a mechanism for improving system performance most significantly in lightly-threaded apps, even at peak loads. But what is the feature's impact on a Gulftown-based Core i7-980X processor with different core counts?

After having looked at AMD’s six-core Phenom II X6 across all of its possible core configurations, it’s time to do the same with Intel’s Core i7-980X flagship. How do performance, power consumption, and power efficiency change when fewer cores are utilized? Is the 32 nm Core i7 top model best with all six cores, or does some combination of fewer core deliver the optimal experience?

The testing we did on AMD's Thuban-based six-core chip revealed two important things.

First, we had to realize that many applications still don't benefit from multiple cores. Users would realize much more performance if software did a better job of supporting the available hardware. We find it frustrating to see AMD and Intel deliver extremely powerful CPUs only to have their potential remain underutilized, especially in mainstream applications.

Our second finding was about efficiency. The Phenom II X6 shows the best performance per watt with all six cores active, as performance gains are more substantial than the additional power required to operate the higher core count.

Is this also the case on Intel’s flagship? Does using all six cores provide the best power efficiency? Will power consumption in idle decrease if we switch off individual cores? Let’s find out.