Investigations by tech site Anandtech have revealed that Samsung has implemented a "BenchmarkBooster" power scheme into its Galaxy S4 smartphones. On the Exynos 5 Octa chip equipped S4 both the CPU and GPU were boosted for certain benchmark programs, on a Qualcomm powered S4 the same boost behaviour is exhibited on the CPU side of things. As an example of what is happening; even when running the most demanding games titles the Exynos GPU never goes faster than 480MHz, yet fire up certain popular 'named' benchmarks and the GPU clock hits 533MHz.
GPU boosting
Anandtech reports that AnTuTu, Quadrant and GLBenchmark 2.5.1 benchmark programs all trigger the Exynos 5 Octa powered Samsung Galaxy S4 to use a 532MHz GPU clock which is not available to any other applications. The successor to GLBenchmark 2.5.1, called GFXBench 2.7.0, doesn't trigger this MHz boost, suggesting that Samsung has software on the S4 which watches for certain program strings. When comparing the GPU triangle throughput results on the same smartphone using these two benchmarks Anandtech saw the boosted device (running GLBenchmark 2.5.1) had a 14 per cent performance increase in triangle throughput performance.
CPU boosting
Using the Android System Monitor Anandtech found similar boosting behaviour affecting the Samsung Galaxy S4 CPU. Using the Exynos 5 Octa handset and firing up the GLBenchmark 2.5.1 caused the big.LITTLE configuration Exynos to switch to the more powerful ARM Cortex A15 cores at 1.2GHz and never drop below that. Again, using the newer version of that benchmark, the lower powered A7 cores could run at 500MHz while no large CPU grunt was required.
The CPU boosting is also present on the Qualcomm variant of the Samsung Galaxy S4, but on the Snapdragon the GPU isn't 'fiddled with'.
BenchmarkBooster strings in an Android APK
Digging around in the APKs on the Samsung Galaxy S4 Anandtech found that 'TwDVFSApp.apk' contained references to a BenchmarkBooster listing (picture above) with minimum clock speed settings and strings listing popular Android benchmarking programs as pictured below:
The conclusion is that Samsung is optimising the Galaxy S4 performance to run repeatable optimal results in popular benchmarks. Anandtech suggests that Samsung either allow these boosted settings for all users/apps or remove them and also stop wasting time on optimising for benchmarks and just optimise for user experience. It will be interesting to see any official response from Samsung about this sneaky behaviour.
UPDATE:
Samsung have issued a statement denying shady behaviour. The firm said that "The maximum GPU frequencies for the GALAXY S4 have been varied to provide optimal user experience for our customers, and were not intended to improve certain benchmark results." Apps such as S Browser, Gallery, Camera and Video Player also run at the maximum GPU frequency of 533MHz for best performance, according to the South Korean electronics giant.
