If Google is splitting the GPU performance in half (2 users per gpu) we should see games running at 1080p/60fps, 1440p/30fps or 4k/30fps with checkerboard rendering. This is PS4 games running at 1080p/30fps. The gpu in Stadia should be more capable than I listed but should be close enough.
The cpu is 2-3x stronger than the PS4 CPU depending how well games are optimized for multicores, this if it's a Intel Xeon 4core, 8thread cpu. We don't have a good way finding this out as the GPU will probably be the bottleneck in almost all scenarios. We should see it in Red dead redemption 2 though, performance should land around 52 average fps in more demanding cpu scenes in that game.
Soon eurogamer will probably have analysis of several games.
6x master league achiever in starcraft2
Beaten Sigrun on God of war mode
Beaten DOOM ultra-nightmare with NO endless ammo-rune, 2x super shotgun and no decoys on ps4 pro.
1-0 against Grubby in Wc3 frozen throne ladder!!
