I have a question to you lot in general, since I don't know a ton about processors.
Its pretty obvious that x86 is ruling the desktop, and it seems ARM has embedded devices as their big thing. Why did the next gen consoles use powerPC processors?
Im not trying to pick a fight or anything, Im just curious. Do they do better in a smaller (physical) machine or less heat or what made them go that way ?
I think it primarily comes down to costs and control. Technical reason are not a primary factor. If Intel or AMD would have sold console makers powerful chips for peanuts many of the consoles would have been happy to use x86 chips, as long as some other critera can be satisfied. The original Xbox did. For Intel/AMD I think it is hard for them to justify to their markets selling powerful chips to console makers for much cheaper than they sell chips to desktop PC makers. When this generation of consoles came out equivalently powered Intel chips to what was in some of the consoles would have cost you closer to the $1000 range than $20 range. You can bet Intel would have cheesed their desktop PC consumers if console makers were getting leading edge chips for $20. With x86 Intel is still able to demand a large premium for their chips at the top end of the market. I am not sure this is very true for many other chip markets.
There are some additional reasons though:
1) Control: Console manufacturers generally want to license or own the chip designs and manufacturing processes where possible to avoid being at the mercy of a single vendor. That is why Microsoft moved away from buying off the shelf Intel chips. This gives them the ability to change manufacturers, reduce costs via further development, integration, etc. The original Xbox became very expensive to produce near the end of its life because the parts in it didn't get cheaper. Those off the shelf parts just got bigger ... you couldn't get 8 gigabyte or whatever drives, microsoft had to buy 120 gigabyte drives for the same price of the original 8 gigabyte one, even though it was useless for them. So for the 360 Microsoft was determined to have more fate over its destiny by gaining more control over these areas.
2) Off the shelf X86 chips are usually more complicated than they need to be in order to cope with the millions of applications developed for X86 over the years. They need to maintain full compatibility with a constantly expanding x86 instruction set, and they try to execute code as efficiently as possible with all sorts of out or order execution hardware, etc. Console manufacturers have the luxury of knowing their hardware will not typically change for the life cycle of the console. This means they can tweak their compilers to generate code that will run efficiently against a single, simpler CPU. They won't include whole areas of instruction sets such as fancy integer extensions because 99% of the expensive code in games is floating point. So what they can do is dedicate less silicon to these areas and more areas of silicon to the things that make games execute efficiently.
With PPC, I believe both the above points are addressed because PPC is more of an industry consortium and is easier to license and develop customized variants of, as well as find places to manufacture chips based on the design.
3) Some consoles were already well along the PPC path from long ago, when PPC was probably thought to have the edge over x86, e.g. GameCube/Wii. Wii basically is a GameCube. So it was very easy for them to continue for reasons of low cost development + backward compatibility. I'd be shocked it the next Nintendo console didn't continue with PPC because of this.
4) Sony wanted to try and push boundaries with CPU designs with Cell. While it does have a PPC component, it's not used for the grunt of processing, the SPUs are. Again it was easy to just license the PPC portion here. Quite frankly I think Sony have kind of worked themselves into a corner with Cell ... I am very curious what PS4 will do when it comes to CPU, or maybe PS5.
Anyway, that's my take on it. What this has to do with Amiga at this juncture in time I am not sure because I am not sure the reasons the console makers went with these chips over 5 years ago has any relevance to what is reality now. I don't think it does.
