On my GNU/Linux KMS/DRM LibRetro/RetroArch setup (using latest stable RetroArch, and using latest GIT code to build the cores), cores show the trademark RetroArch video synchronization that results on totally smooth scrolls in games.
All, except Dosbox Pure: As with previous Dosbox LR core, this core is not synchronizing video emulation with the host video frequency, resulting on hiccups/desync once in a while. So, what is the mistery with DOS emulators on RetroArch? Is it not possible to synchronize them as with the rest of the cores? I have changed the max audio skew to 0.50 (that would be more than sufficient for 70Hz vs 60Hz differences) but still, the core is not synchronizing and scrolls in DOS games like Super Frog and Pinball Dreams are poor.