The PS4 is a great console, It has a CPU with 8 little cores that achieves a Core I3 like multithreading performance, a nice 18 core shader graphic card derived from Radeon HD 7870-7850 that gives 1,84 Tflops and 8 GB of DDR5 with 176 GB/s of Bandwith. With these specifications it can run almost every game at 1080p 30 FPS. It could have been a little more powerfull, but its enough for 1080p mantaining a good console size and power consumption.
Now, what do you think the next PS5 will bring us in terms of hardware specifications? I think next gen console should be able to handle at least 4k Resolution at 30 FPS to take advantage of new TVs. What do you think should be the capabilities and hardware of the next sony console if it comes arround 2019-2020 to convince you to buy it?
2019 would be the latest I think it might come out (Expect sooner). But when it does I would expect:
-Something like an R9 770X or whatever would be like 8 times stronger than the 7870 in the PS4
-16 or 32GB of HBM memory bringing the bandwidth to 1 or 2 TB/s
-An 8-core CPU clocked at 3 - 4.0 GHz with much better IPC than the PS4's cpu, and a second quad-core cpu for background tasks.
-Full backwords compatibility with the PS4.
-Expect the PS5 to perform as well at 4K as the PS4 does at 1080p now with the obvious advantage of much better effects/AI/Physics. 60 FPS should also be at least decently easier for the PS5 to do than it is for the current consoles (Due to the faster CPU and RAM).
-Possibly a 1 TB SSD for fast load times. Expect at least a hybrid solution.
What makes you think that's enough to do 4K at 30fps? Thats a 4x increase in resolution, while ps4 already has trouble maintaining 30 fps with a 2.25 increase in resolution.
An 8x faster GPU with 10x faster memory bandwidth would handle the 4x increase in resolution, unless the extra power is used on bigger effects.
With the pixels being finer, they can reduce some things like anti-aliasing as well. For example on a regular PC monitor, you need LCD sub-pixel font rendering to make text look nice, but on a Retina resoution screen the pixels are so fine that you don't need sub-pixel fonts.