The Samsung Galaxy S4 runs an Exynos 5 Octa central processing unit with multiple cores and a GPU, or graphical processing unit, that hums along at 480 MHz GPU.
Unless, of course, you’re running benchmarking applications.
In February a forum member at Beyond3D suggested that Samsung overclocks the GPU to 532 MHz while running benchmarking tests that are intended to demonstrate how powerful the processing unit is, while throttling it to just 480 MHz when in actual use. AnandTech recently tested and researched the claims, and discovered code that Samsung uses to speed up the processor when — and only when — running popular speed testing suites such as GLBenchmark, AnTuTu, or Quadrant.
Some might call that optimization. Others might say it’s battery-saving. And some are saying it’s just plain cheating. You can count the original discoverer, Andrei F., in that last category:
“Oh hell Samsung, shame on you!” he wrote, adding in a tweet that Samsung was “cheating GPU benchmarks,” again.
The switch has real, everyday consequences, especially for mobile gamers who might be choosing a device based on how well they can play their favorite games. Faster GPUs push more polygons, making gameplay smoother, more realistic, and more immersive.
It’s not just the GPU, AnandTech discovered. It’s also the CPU.
Certain benchmarking suites, such as GLBenchmark, trigger the CPU to jump to 1.2 GHz, while others, such as GFXBench, are not triggered, and use a default CPU speed with lower performance, at just 250 MHz. Other benchmarking apps trigger different CPU speeds, with Linpack inspiring Samsung to offer up 1.6 GHz and Snapdragon hitting the same heights as GLBenchmark, 1.9 GHz.
Samsung apparently uses a settings application, TwDVFSApp.apk, which includes hard-coded CPU settings for the different benchmarks, among them a “boost mode” that kicks the CPU and GPU into high gear.
Gaming benchmarks is no new game; it’s been happening ever since enthusiasts starting comparing Apple’s PowerPC processors to Intel’s x86 CPUs. In most cases, however, what’s going on is a deliberate attempt to maximize the attractiveness and perceived power of a particular chip while reserving that power only for artificial testing situations.
As such, it’s ethically questionable, at least.
I’ve asked Samsung to explain what’s happening here. As the company responds, I’ll update this post.