updated 08:42 pm EDT, Tue July 30, 2013
Certain benchmarking utilities granted exceptions for max speed
Possibly in an effort to influence press coverage, Samsung has been found to be optimizing code in the Galaxy S4 smartphone specifically for benchmarking applications, allowing certain utilities to push the graphical processing unit (GPU) and central processing unit (CPU) to maximum speed for the purposes of the test. In every other application tested, the processors never reached maximum speed, throttled by a coded limit, presumably to limit thermal buildup within the smartphone.
A report by Anandtech found that running "even the most demanding titles," the GPU never ran any faster than 480MHz. However, popular Android benchmarking utility GLBenchmark boosts the GPU clock speed to 532MHz. A similar benchmarking utility, GFXBench 2.7.0 didn't experience the boost.
A similar test was performed with the CPU, finding a default frequency of 1.2GHz, even when sitting idle at the menu screen of the benchmarking utility. Other benchmarking tools never pushed the Cortex A7 faster than 500MHz. Similar clock speed behavior exists on both the US and International versions of the smartphone.
Delving deeper into the issue, Anandtech found an application looking at executable names and boosting processor speeds depending on the title of the app. One specific line, titled "benchmark booster" lists a series of popular metering applications subject to the CPU and GPU clock speed increase.
Benchmarks are artificial statistics representing maximum speeds of a processor, which bears little relevancy to actual use but see heavy use in marketing materials. At no point are the processors in the Galaxy S4 pushed greater than rated speeds by the hardcoded exception list. The benchmarks could be viewed as theoretically accurate for the advertised limits of the processor, but with limits placed in real-world applications. As it stands, smartphone processor speeds vary wildly depending on the environment, with both thermal conditions and battery life being primary determiners of clock speed.
Anandtech believes that "what Samsung needs to do going forward is either open up these settings for all users/applications (e.g. offer a configurable setting that fixes the CPU governor in a high performance mode, and unlocks the 532MHz GPU frequency) or remove the optimization altogether. The risk of doing nothing is that we end up in an arms race between all of the SoC and device makers where non-insignificant amounts of time and engineering effort is spent on gaming the benchmarks rather than improving user experience. Optimizing for user experience is all that's necessary, good benchmarks benefit indirectly -- those that don't will eventually become irrelevant."