The OnePlus 3T had a less responsive touchscreen than similar flagship devices when released and unfortunately this remains after the software update to OxygenOS 4.0, based on Android 7.0 Nougat. This phenomena is known as "touch latency," which describes the lag between moving a finger on the touchscreen and the device responding. Now that the update to Android 7.0 Nougat has arrived, customers have had the opportunity to see how responsive the OnePlus smartphones are with the update and unfortunately, high screen latency is still an issue. There are a number of short video clips comparing the OnePlus 3T with a number of flagship devices which showcase this particular issue in action.
The issue of touch latency was initially brought up back in late November of last year after a number of customers complained about it, which gave the impression that the devices were sluggish. Touch latency times of the OnePlus 3 and OnePlus 3T models were given of close to 100 ms, around twice that of contemporary flagship devices such as the HTC 10 and Samsung Galaxy S7. Following initial reports of the OnePlus 3 and OnePlus 3T's sluggish screen response, OnePlus' founder Carl Pei Tweeted that the company was aware of the issue but that the software update to Android 7.0 Nougat would be the priority. OnePlus had set itself a deadline of shipping an Android Nougat-based ROM to customers by the end of the year and as it happened, delivered on the promise but on New Year's Eve. However, Pei explained that the development team "…will have a touch latency optimization with the Nougat build that will come to both the OnePlus 3 and OnePlus 3T by the end of the year." Unfortunately, OnePlus do not appear to have implemented the touchscreen optimization fix.
The issue has been discussed on a number of Internet websites, including the XDA Forums and Reddit. One XDA Forums member believes that the problem lies in the "move sensitivity" setting in the device's firmware, which is set too high. This means that if one places a finger onto the OnePlus 3T's touchscreen and start to slowly move it, the screen hesitates or lags before it starts to move. Other devices do not have the same lag. The effect of this issue means that typing quickly is described as "super painful because of latency," according to a OnePlus forum contributor earlier in the month. This slower response time is not what one would expect from a high end device powered by the current Qualcomm flagship CPU, the Snapdragon 821, backed up by a healthy 6 GB of RAM. OnePlus' update to OxygenOS 4.0 for both the OnePlus 3 and OnePlus 3T has also not been without other issues, such as Wi-Fi connectivity. While there has already been an incremental update for the OnePlus 3T to OxygenOS 4.0.2, there still appears to be more work that needs to be completed.