GPD has shed light on the potential frame rate micro-stuttering issues we encountered when reviewing the Win 4 last month. To recap, we observed the following when testing frame rate stability using The Witcher 3:
...performance would start out high at over 80 FPS before steadily falling to 65 FPS with constant fluctuations. While the performance drop over time is not unusual, the fluctuations are abnormal and they result in periodic micro-stuttering during gameplay. We tested this twice just to be sure and the results would not improve. Unoptimized CPU utilization of background tasks or applications is typically the cause of such behavior when gaming.
Seemingly, the micro-stuttering we observed has nothing to do with the Ryzen 7 6800U and GPD's optimisation of it. Others have since noticed this micro-stuttering, which has been discussed at length on GPD's Discord and on Reddit. However, GPD has now outlined that this is caused by 'the vertical to horizontal screen IC conversion' and not our previous theory. For context, most gaming handhelds ship with portrait displays, which can cause issues when running older games in Windows. Please see The Phawx's explanation for more details.
Thus, it appears that the company has not informed people the whole truth about the Win 4's 'native landscape screen', even if it appears to act as such. Apparently, setting custom frame rates just below 60 Hz resolves the issue, but people's mileage has varied so far. Regardless, The Phawx claims that 'GPD is aware' of the issue and is 'working on a fix'. It remains to be seen whether this will be a hardware or software fix yet though, nor when GPD will be capable of delivering it.