Sony enabled PS2 backwards compatibility for the PS4 without telling anyone

I happened to get the Star Wars Battlefront PS4 bundle and found something weird with Star Wars Bounty Hunter. It looks beautiful so I decided to enable progressive scan mode like I do on my PS2. The results are terrible. The image quality is terrible, the screen is shorter vertically, and the image is quite shaky. Setting the PS4 to 480p does not fix it either.

 

First of all, the PS4 CPU is not "much weaker" than the Cell BE in the PS3. Generally its difficult to compare different architectures, but we can get a rough estimate by looking at the number of floating point operations per second (FLOPS) that the processor can achieve. Some quick googling reveals the following:

1. "PlayStation 3's Cell CPU achieves a theoretical maximum of 23.04 GFLOPS in single precision floating point operations" (https://en.wikipedia.org/wiki/PlayStation_3_technical_specifications)
2. PS4 CPU has 102 GFLOPS (http://www.vgleaks.com/playstation-4-xbox-one-comparison-chart)

Therefore the PS4 has nearly 5 times the raw power of a PS3 operating at the absolute theoretical maximum. That said because of the complexity of the Cell architecture as well as the fact that 2 of the cores are disabled, you'd be lucky to get half that in the general case.

You're sort of on the right track with your second paragraph when you say that reusing the Cell architecture would have been the best way to ensure backwards compatibility. In fact what Sony could have done was create a new revision of the CBE with a much more powerful PPE core (perhaps multiple) and then instead of having 8 SPEs on the die add like 100! Then when its time to play a PS3 game you just restrict the CPU to only use 1 downclocked PPE core and 8 of the SPEs. Then it would appear exactly like a ps3 and as an added bonus there is already support for PS1 and PS2 software emulation programmed for the PS3. If sony did this they could have had backwards compatibility all the way back to the PS1!

-doulomb