Microsoft’s xCloud game streaming seems to sink to a lower visual quality setting when running on Linux. The apparent downgrade across operating systems was noted by a Reddit user over the holiday weekend and confirmed in Ars’ own testing this morning.
To compare how xCloud handles a Linux machine versus a Windows machine, an Edge extension was used during testing to force the browser’s User-Agent string to present itself as a Linux browser:
- Windows User-Agent tested: Mozilla / 5.0 (Windows NT 10.0; Win64; x64) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 103.0.5060.66 Safari / 537.36 Edg / 103.0.1264.44
- Linux User-Agent tested: Mozilla / 5.0 (X11; Linux x86_64) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 102.0.5005.27 Safari / 537.36 Edg / 102.0.1245.7
Tests were performed on the latest version of Microsoft Edge (version 103.0.1264.44, 64-bit) running on a Windows 10 PC. All tests were run on a wired Internet connection that recorded 120 Mbps and ~ 9 ms latency download speeds, according to spot tests on Fast.com.
The difference in stream quality can be seen in the gallery above (expand the images to full screen for better viewing). With the Linux User-Agent, the edges are generally less sharp and the colors a little more washed out. The difference is even more obvious if you zoom in on Force logo and menu text, which shows a significant reduction in clarity.
What’s going on here?
Interestingly, the drop in quality seems to disappear if you enable “Clarity Boost, an Edge-exclusive feature that” provides[es] the optimal look and feel while playing Xbox games from the cloud, “according to Microsoft. It’s great for Linux users who switched to Microsoft Edge when it launched on Linux in November last year. But Linux users who stick to Firefox, Chrome or other browsers are currently stuck with seemingly reduced power quality.
The decline in Linux quality has led some to speculate that Microsoft is trying to reserve the best xCloud streaming performance for Windows computers in an effort to attract more users to its own operating system. However, using a Macintosh User-Agent string provides a power performance similar to that of Windows, which would seem to be a major omission if that theory were true. Microsoft has also not released any form of “best on Windows” -style marketing to promote xCloud streaming, which would apparently be a key component in trying to attract new Windows users.
(The quality difference may be a roundabout attempt to get Linux users to switch to the Edge browser, where Clarity Boost offers the best possible quality. However, it will not fully explain why Windows users on other browsers, without Clarity Boost, also get better power quality than their Linux brothers.)
Others have suggested that the downgrade may simply be a bug caused by Microsoft’s naive analysis of the User-Agent strings. This is because the User-Agent strings for Android browsers generally identify themselves as a version of Linux (“Linux; Android 11; HD1905,” for example). Microsoft’s xCloud code can simply see “Linux” in that string, assume the user is running Android, and then automatically choke the power quality to account for the (presumably) reduced screen size of an Android phone or tablet.
With Microsoft rejecting an opportunity to comment on Ars Technica, we are still stuck in the theorizing about what lies behind this apparent problem. For now, however, Linux users who want the best xCloud performance will switch to Microsoft Edge with Clarity Boost or at least the fake User-Agent settings to pretend to run Windows.