In our last TouchMarks report, we looked at the touchscreen latencies of the flagship smartphones from different manufacturers. In this report, we’ll benchmark the touchscreen latencies of the leading tablets, including iPads, Microsoft’s Surface and leading Android tablets including Amazon’s newest Kindle Fire HD.
Before we get into the results, a little bit about our methodology (for a full recap please check out our first post. In TouchMarks, we use our Touchscope to benchmark the App Response Time of touchscreen devices by measuring the time between when the user touches the screen and the device updates the display. We place the light sensor and touch at the center of the screen to account for the device’s 60 Hz refresh rate, the devices are in airplane mode with full brightness and they have had all background apps closed to make the test as fair as possible.
For this report, we will specifically be measuring the Minimum App Response Time by using OpenGL/DirectX-based optimized apps with minimal logic to quickly flash the screen white in response to a touch. We’ve open sourced the apps here for review. If you think there is a material discrepancy between our test apps on the different operating systems that gives one device an unfair advantage over the other, please let us know in the comments or submit a pull request.
With that, let’s take a look at the results!
For this report, we benchmarked the latest versions of popular tablets from various manufacturers, including Amazon’s brand new Kindle Fire HD. We also threw Nvidia’s new Tegra 4-based SHIELD in there even though it’s not a traditional tablet. Here’s a graph of the results:
In a result that’s perhaps now unsurprising, the iOS devices are more responsive than its competitors. Interestingly, the iPad mini – with its smaller screen and 1024×768 resolution – performs similarly to the larger fourth generation iPad and its 2048×1536 resolution, suggesting that responsiveness is not reduced by the larger screen size or resolution.
Perhaps the more interesting results are in the non-iOS devices. Nvidia’s SHIELD performed much better (though strangely with much higher variance) than the other Android devices, suggesting that Nvidia went through special effort to optimize the responsiveness of the device. It’ll be interesting to see whether the improvement carries over to other, non-Nvidia Tegra 4-based devices.
Amazon’s Kindle Fire HD was a surprising leader in the Android section, especially given that it’s $90+ cheaper than the other two Android tablets. This could be a result of Amazon’s willingness to sell expensive hardware at a loss. Finally, Microsoft’s Surface RT also performed much better than we expected, especially given that Nokia’s Lumia also running Windows didn’t fare significantly better than Android devices in our smartphone comparison. Given these results, I’m especially excited to run Amazon’s higher-end Kindle HDX and Microsoft’s new Surface 2 through our Touchscope. I’ll be updating this post with the results as soon as I can get my hands on them.
Our previous speculations continue to apply – more responsive devices may process touches earlier in the stack, poll for touches more frequently or have touchscreens optimized or calibrated to be more responsive. In our latest review of our test apps, we discovered an optimization that suggests that the GPU or GPU drivers in the devices might also add significant latency. We will explore the ramifications of this and possible explanations in a future TouchMarks, but note our current test apps do not include the optimization in order to better represent the performance of normal OpenGL/DirectX apps.
Conclusion: if you primarily use your tablet for reading, watching videos or browsing the web, then shop around and pick the best tablet – iOS, Android, Windows 8 – that suits your needs. With their lower price points and high PPI screens you may find an Android tablet works perfectly for you. If, however, you’re into latency-sensitive applications like games or interactive music apps, then your best bet might be an iPad.