GCN 1st gen 384:24:8 , CPU dual core 4 threads. Comparable to the 1st gen i5 they require as minimum.
Found a video with the Radeon M330 GCN 1st gen 320:20:8
At 1024x768 they were managing 50 or so FPS. Granted they had a much faster CPU.
Another video A6 APU with R4 level graphics, 720p low settings, getting at least 30FPS.
View: https://www.youtube.com/watch?v=aLtaSPEhIkA
Depends on what you mean by playable. It won't be nice looking or super competitive, but it should play.