Samsung has been forced to respond to a detailed technical breakdown of its flagship Galaxy S4's benchmarking performance, in which tech site AnandTech claims code in the phone specifically overclocks the phone's processor to give an unrealistic score for some widely used benchmarking tools.
Tipped off by a post on the Beyond3D forum, the site ran a variety of commonly used benchmarks and kept a close eye on the Galaxy S4's central processor and graphics processor clock speeds. It found that the phone seemed to increase its clock speed when running certain benchmarks.
This is backed up by a string of code found on the phone that AnandTech says is marked 'BenchmarkBooster' and specifically names Quadrant, LinPack and AnTuTu as apps that should trigger the higher clock speed.
Benchmarking software is routinely used in gadget reviews, including CNET UK's, to give a comparison of computing power between different devices. Samsung's high-end Galaxy phones generally do extremely well in these comparisons and have a reputation for being more powerful than other brands.
What AnandTech seems to be suggesting is the phone is overclocking itself -- that is, running faster than it is normally restricted to -- in order to get a better score, so it seems more powerful than it actually would be in normal use.
Samsung denied that was the case in a statement to CNET UK. "Under ordinary conditions, the Galaxy S4 has been designed to allow a maximum GPU frequency of 533MHz," the company says. "However, the maximum GPU frequency is lowered to 480MHz for certain gaming apps that may cause an overload, when they are used for a prolonged period of time in full-screen mode.
"Meanwhile, a maximum GPU frequency of 533MHz is applicable for running apps that are usually used in full-screen mode, such as the S Browser, gallery, camera, video player, and certain benchmarking apps, which also demand substantial performance.
"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."
It's not clear how widely that 480MHz cap is applied. Samsung doesn't advertise the specific clock speed of the GPU on its official specs page.
Also unclear is whether this affects all versions of the S4 -- AnandTech mainly tested the non-UK version with the eight-core Exynos chip. It said CPU behaviour was the same for the Qualcomm quad-core version, but didn't mention GPUs for that model.
We use various tests in CNET UK reviews to give you a comprehensive picture of how a phone performs, including cross-platform benchmarking tools. We use Geekbench (which isn't mentioned in the report) and Quadrant (which is), but always stress they're a pretty arbitrary comparison point. We also test specific high-end games and HD video and see how smoothly they play, a more realistic measure of whether you can have fun with the device.
Do you think it's odd that Samsung has set up exemptions for particular benchmarks? Is the S4 more than powerful enough anyway? Let me know what you think in the comments, or on our high-performance Facebook page.