Benchmark Results: Adobe Photoshop CS 5
Our Photoshop benchmark consists of four threaded filters applied to a large (~15 MB) TIFF image in a script, which effectively demonstrates the performance of each processor in a real-world application. Naturally, the CPUs best optimized for threaded tend to rise to the top.
Unfortunately, that's not the case absolutely. Both the Core i7-3720QM and Core i7-2820QM do really well, the Ivy Bridge-based design trumping Sandy Bridge. As expected, our dual-core Arrandale-based sample performs a lot worse, eating up almost four minutes to finish the same task. But then, surprisingly, AMD's quad-core A8-3520M eats up an additional two minutes.
Seemingly, sharing a 35 W TDP between graphics and processing cores is a real handicap for the APU. So, let's take a look at how utilization and power consumption come into play. In a mobile environment, those two variables are important as well, after all.
As mentioned, our filters are threaded, which explains why even the fastest quad-core chip is pegged at 100% throughout the test. And the performance picture is once again painted by the lines where each CPU drops back to near-zero, indicating the task is complete.
But it takes a look at the power consumption chart to reveal how much battery life each of these platforms is going to gobble up as it gets its job done. The Core i7-3720QM is a 45 W chip, and its system power use hovers in the 40 W range. The older Sandy Bridge-based part, Core i7-2820QM, is also a 45 W processor. Its system power use spikes much higher, though. The Core i5-460M is a 35 W CPU that nearly matches Ivy Bridge's power use, despite its far inferior performance. AMD's A8, also rated for 35 W, clearly underperforms the other contenders. However, it hovers between 20 and 30 W total power use.
Now, that'd be great if the A8 got its job done faster. Using less power over a long period of time doesn't turn out to be a benefit. In terms of energy efficiency, even the Core i7-2820QM outperforms AMD's A8-3520M because it consumes a little more than two times as much power, but finishes the job in one-third of the time. Ivy Bridge improves on that to an even greater degree.