I think they say the PS3 has way more processing power than PC's?
I hope you're joking

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All games are ofc coded/designed on a PC/MAC. But the majority of them For consoles like the recent gta's. Then they are ported over if they decide to release it on PC also. Which tends to result in a mess (at least for rockstar) due to the coding and design being for console hardware and architecture. They're soooooo many limits on ps3 and xbox due to the 7+ yr old hardware that its not even funny. Draw distance, and ammount of models showing simuntainusly and polygon counts etc. Which they cant really do anything about. They're just really good at optimizing it since they have been doing it for so long. But new consoles will offer a Brand new world.
Take car rendering in gta for example. When you Finally find a exclusive sports car and start driving it. What happends? Suddenly a Bunch of simular cars ends up driving all around on on the road. Why? Because the console cant handle rendering a Bunch of different car models since its too demanding. What is less demanding is copying cars that have already been rendered for example ...the car you're driving it. This will also be noticeable in the new gta. But not with games on the next generation.
Not even going into the whole FPS issue with consoles since juding by your post you couldn't relate to that anyway.
I just hope we don't have to wait 5+ years for a gta developed from the Ground up on the new generation. That will be Mindblowing compared to anything released up to this point Including gta V. (A gta developed on the ground up for current high end computer would blow the next generation consoles and the generation following that out of the water) but there's not enough money in PC for them to do that.
They have mentoned (game developers) that we can expect brtter port from ps4/One though due to the architecture being more simular atleast. or something like that.
Games have the potential and have had the potential to look fucking incredible for many years now but the consoles have been holdign it back due to the old ass hardware and due to the fact that there's where the money is at. So the developers have to Really hold back on what they're doing so the consoles can run it decently.