Whereas the original PS4 features an eight-core CPU with a 1.6GHz clockspeed, the new model is expected to offer a 2.1GHz frequency. The GPU upgrade is expected to be more substantial, the old model has an AMD GCN GPU with 18 CUs and a 800MHz frequency and 8GB GDDR5 memory with 176GB/s bandwidth, whereas the PlayStation 4 "Neo" reportedly offers an improved AMD GCN based GPU with 36 CUs, a 911MHz clockspeed and 8GB GDDR5 memory with a memory bandwidth of 218GB/s. Perhaps this is a major design win for AMD's upcoming Polaris GPU.
Starting in October, Sony will reportedly demand every PS4 game to ship with both a "Base Mode" for the current PS4 and a "NEO Mode" for the new console. Neo games will be able to take advantage of the improved hardware, the console will be able to output 4K but games themselves will not be required to be 4K native. This suggests 4K will probably be done by upscaling Full HD as games need to hit a minimum frame rate and that's not very realistic given the hardware specifications of the Neo.
In the documents we’ve received, Sony offers suggestions for reaching 4K/UltraHD resolutions for NEO mode game builds, but they're also giving developers a degree of freedom with how to approach this. 4K TV owners should expect the NEO to upscale games to fit the format, but one place Sony is unwilling to bend is on frame rate. Throughout the documents, Sony repeatedly reminds developers that the frame rate of games in NEO Mode must meet or exceed the frame rate of the game on the original PS4 system.Pricing of the new console is said to be $399 but the launch date is still a mystery. The site also claims older games can take advantage of the Neo hardware upgrade, but this will require patches from developers.