A Look at Real World Performance of an Overclocked Phone
In order to test just how practical overclocking an Android device really is, we set up a test device, ran it through a bunch of benchmarks and tests, overclocked it, and ran it through those benchmarks and tests again. Our test device was the Samsung Nexus S. At fifteen months old and starting to show a bit of stutter with a bunch of apps installed, it made an excellent candidate.
We were easily able to bring the 1GHz processor up to 1.4GHz, which you might think would suggest a 40% increase in performance, but in most benchmarks, we saw nowhere near that kind of a gain. The CPU is just one part of the entire system. Overclocking your Android typically won’t affect the GPU or memory and storage busses. Overall, that 40% clock boost was more like a 10-20% system-wide boost on average.
| Benchmark Suites | |||
|---|---|---|---|
| Stock Speeds | 1.4GHz Overclock | Percent Increase | |
| Quadrant | 1218 | 1462 | 20.0% |
| Smartbench 2012 Productivity Index | 497 | 617 | 24.1% |
| Smartbench 2012 Game Index | 1796 | 2060 | 14.7% |
| Anatu | 3105 | 3723 | 19.9% |
| Average Score | 19.7% |
Looking at the benchmarks that test overall system performance, it’s clear that some do give preference to CPU speed, particularly Smartbench 2012’s Productivity Index, but the average increase across all of the benchmarks is just under 20%.
| Gaming Benchmarks | |||
|---|---|---|---|
| Stock Speeds | 1.4GHz Overclock | Percent Increase | |
| Nenamark1 (FPS) | 54.5 | 55.2 | 1.3% |
| Nenamark2 (FPS) | 24.7 | 25.7 | 4.0% |
| Neocore (FPS) | 55.5 | 55.7 | 0.4% |
| Electopia (FPS) | 18.88 | 18.89 | 0.1% |
| Average Score | 1.4% |
As we can see with the gaming benchmarks, GPU dependent games see very little gain from overclocking, though we think it’s important to note that the results from Nenamark1 and Neocore appear to be limited by the refresh rate of the screen. Nenamark2 and Electopia aren’t affected by this issue, however, and neither show much improvement in 3D gaming. It’s a pretty safe bet that overclocking your Android phone won’t make a choppy game more playable.
| Linpack | |||
|---|---|---|---|
| Stock Speeds | 1.4GHz Overclock | Percent Increase | |
| Linpack Score (lower is better) | 4.97 | 3.62 | 27.2% |
| Score in MFLOPS (higher is better) | 16.8 | 23.6 | 40.50% |
| Average Score | 33.8% |
Linpack, which is heavily CPU dependent, showed the most gain after overclocking. Actions that are primarily CPU intensive, such as system navigation, web browsing, and general productivity apps, appeared noticeably more responsive; however, this was not entirely due to overclocking. We started noticing these improvements after flashing the custom kernel, but before overclocking. Overclocking did improve overall smoothness further, but tweaks from the custom kernel also played a big part.
Battery Life
While on paper, overclocking while undervolting results in increased battery life, actually testing and measuring this increase was a bit more difficult. Most smartphone battery testing metrics run the system at 100% load with the screen on full brightness in order to get a consistent test. During this test, the overclocked settings got roughly 15% worse battery life than the stock speeds due to the 1.4GHz clock rate requiring a higher voltage to sustain.
In a real-world scenario, your phone would spend a large portion of its time in a low power state which would be largely benefited by the custom kernel’s undervolted settings. Additionally, the overclocked high power state would allow it to finish its workload faster and return to a low power state sooner. Theoretically, this would result in less power draw overall. Unfortunately, it’s very difficult to test in a short amount of time; however, while trying to keep daily use as equal as possible, we did see a small increase in battery life of about 12% with the overclocked and undervolted settings. Due to time constraints we weren’t able to test how much of this was strictly thanks to special kernel features versus the overclocking itself.
Ultimately, we discovered that overclocking your Android really isn’t about performance gains. It’s enough to take a borderline laggy device and make it run smoothly again, but it likely won’t make your games run much faster. The byproducts of overclocking, such as the improved kernel, added features, and extra battery life, are really what make it worthwhile.
