Question about the 360 and PS3 cpu

[Hyperactive Slob]

I have read in some articles that cell and xbox360's CPU won't allow developers to make clever and dynamic AI because of it's in-order procesing. I would appreciated if someone could enlighten me on the subject?

[Denz]

I made a little search on google and find nothing about it, i am wondering this too.

[Twin]

i have no idea :p

what i do know (or atleast what i read) is that the ps3 has been developed in such a way that it'll be almost impossible to port games from/to the ps3...

don't know if that helps...but i'm guessing the AI thing is BS because both the 360 and ps3 have alot of processing power so i can't see why they wouldn't beable to perform some kind of dynamic AI...

actually if i remember correctly, every time i play something like ghost recon the computer controlled players will do react to something different every time...not sure if that's dynamic AI though...and if the 360 can do it, the ps3 will beable to do it since they're both pretty much identical

[Drazula]

I have not seen anything like that. Just guessing though, I would say this is false because a developer could simply keep the AI in the same thread as the object it is tied to.

[FireFly]

In-order processing basically means that the programmer's instructions are executed in the order they're written - the CPU doesn't dynamically reorder them for optimum execution times. This means that when porting code straight over from the PC it will run at half the speed.

"But if you look at the current platforms, in many ways, it’s not quite as powerful as it sounds if you add up all the numbers and flops and things like that. If you just take code designed for an x86 that’s running on a Pentium or Athlon or something, and you run it on either of the PowerPCs from these new consoles, it’ll run at about half the speed of a modern state of the art system, and that’s because they’re in-order processors, they’re not out-of-order execution or speculative, any of the things that go on in modern high-end PC processors. And while the gigahertz looks really good on there, you have to take it with this kind of “divide by two” effect going on there."

http://www.beyond3d.com/forum/showthread.php?t=22648

However programmers can reduce the hit by optimising the code themselves, and they can still scale performance over multiple threads. So no, there's no reason why you can't run complex A.I routines on the 360. You just might need to use multiple threads/cores to achieve acceptable performance.

[Kristian Joensen]

Is the Cell inorder or out of order ? I thought that one fo the two was in order and the other out of order, was I wrong are both inorder ?

[FireFly]

Both are in-order. Both are made by IBM, and each core in the 360 is equivalent to the single PPE in the Cell. Microsoft approached IBM after the Cell deal, and were looking for a quick solution, so IBM offered them the PowerPC core that they'd developed for Sony.

[Phayzon]

Meh, as long as something shoots back in single player I dont care what happens really. :p :tinyted: Will the 360's FEAR have as good of AI as the PC version?

[Duoae]

I only have one quote from last year's GDC when one of the panelists (a developer) was complaining that all we will see is pretty versions of the same games because the in-order processing limited what could be achieved on this next generation.

Found the quote but i don't think it's at the site i read it at recently. There's a better transcription:

Chris HeckerSo, as you know, graphics and physics grind on large homogenous floating point data structures in a very straight-line structured way. Then we have AI and gameplay code. Lots of exceptions, tunable parameters, indirections and often messy. We hate this code, it’s a mess, but this is the code that makes the game DIFFERENT. Here is the terrifying realization about the next generation consoles: I’m about to break a ton of NDAs here, oh well, haha, I never signed them anyway.

http://crystaltips.typepad.com/wonderland/2005/03/burn_the_house_.html

Here's a better transcription of the event:
http://uk.gamespot.com/news/2005/03/18/news_6120449.html?sid=6120449