PS4 gives 4.5GB to games + an additional 1GB that might be able to be used. Along with 6 Cores on the CPU can be used, 7th core was unlocked recently running at 1.6GHz.
Xbox One gives around 5GB to games + 32mb of Embedded Ram on the GPU. Again like the PS4, it had 6 Cores on the CPU to be used, but 7th core was unlocked recently. Also the speed was increased from 1.6Ghz to 1.73Ghz after launch via firm ware update.
Since release the ram to be used for games seems unchanged from anything out there for both consoles. The ram seems to be partially limiting the potential for some games.