Xbox 360 & PS3 COD 3 Tech Questions

I thought all versions were being done internally by Activision!?

I don't know either way. I just figured the reason it looks so poo must be because its being coded by Guatamalan child labor or something. :devilish:

It's a super Gamecube, not a PS1 for pete's sake!
 
I don't think that's particularly true. Every console has strengths and weaknesses, but you can't overlook the fact PS3 has a stonking great Cell processor in it that's pretty good at some of these graphics things and lends a lot of support to rendering. Adding some extra effects to PS3 games could just be a matter of PS3 having more processing hardware to throw at the problem. Similarly on XB360 you may find effects that are possible because of eDRAM or some other configuration that can't be done on PS3 (when keeping everything else equal).

If we assume the GPUs in both consoles are approximately capable, the key differentiating factor between the machines is the CPU, and if Cell can be leveraged (the old question being could devs actually make any use of it?) then PS3 ought to be doing more calculations per frame. Thus I don't find it surprising that PS3 might show some features over XB360 in multiplayer titles, other than the fact I'm surprised development teams would bother as it's more work for them and at what gains?!

I think I adequately summarised that viewpoint in my mention of "secondary factors." I don't think there is such a significant reserve of graphics processing power in Cell that the same effects can't be done on the 360. The differences will be in the approaches used to realized the effects, and the amount of resources necessary to develop those approaches. Whatever "novel" things you see on one console, I'm sure that with time you will/could see on the other (i.e., an effect easy to add with Cell or Xenos could probably be done on the other given more time to tweak).
 
In an old EGM issue (June) a developer stated that the Xbox 360 and PS3 versions of COD 3 will look the same, except that the PS3 version will have more light sources and other touches.


there is another trivial difference (I'm sarcastic here) :
the x360 version runs at double the framerate of the ps3 version (I'm serious here)
 
I think I adequately summarised that viewpoint in my mention of "secondary factors." I don't think there is such a significant reserve of graphics processing power in Cell that the same effects can't be done on the 360.
That's where we differ in opinion. You count Cell as a 'quirk' in PS3 that'll make something a bit easier or what have you. I count Cell as a very strong component for performing tasks that XB360 hasn't got the processing hardware to match. I don't think that every game on PS3 can be ported to XB360 with the same quality, just with more time and effort spent to get there (and vice versa). There will be things on one platform unique to that platform that time and effort won't be able to add to the other one.
 
The CELL will obviously provide large performance gains when it comes to AI, Physics, Animation, Sound, and other computationally intensive processes. What's not as clear in my opinion is *just how much* of a boost it's power will give to the graphical pipeline of the PS3. We know by now that it can do pixel shading, vertex work, help with lighting, and even post process work. But what we don't know is just how much the extra processing power of the CELL can be used efficently for the above processes. Also, we don't know how much power will be remaining for the CELL to utilize after being used for so many other non-graphical tasks.

One thing that has me encouraged is that I saw a trailer of Ted Price from Insomniac games stating that they were assigning different SPE's for different tasks. He said they were using a few for physics, one for sound, one for lighting, and so fourth. However, from what I have read in most cases that's probably the least efficent way to get the most from the CELL. The most efficent way is to break up each of those processes into perhaps dozens of tiny threads that will stream from SPE to SPE. When one SPE finishes a tiny part of a task then it will automatically ask for another, and all the SPE's stay busy.

If they are not utilizing advanced programming methods such as that yet for a GREAT looking game like RFOM then just imagine when they really start diving into the CELL.
 
there is another trivial difference (I'm sarcastic here) :
the x360 version runs at double the framerate of the ps3 version (I'm serious here)


Ok, so what's the source for this? I know one site that made this claim, but there is absolutely no evidence or even a source for this. And even if it was like that the 360 version is far more advanced in development, due to the predecessor...

The official dev statement was and still is: both versions look identical, texture and geometry wise, but with greatly enhanced lighting on the PS3 side. Everything else is pure speculation.
 
The CELL will obviously provide large performance gains when it comes to AI, Physics, Animation, Sound, and other computationally intensive processes. What's not as clear in my opinion is *just how much* of a boost it's power will give to the graphical pipeline of the PS3. We know by now that it can do pixel shading, vertex work, help with lighting, and even post process work. But what we don't know is just how much the extra processing power of the CELL can be used efficently for the above processes. Also, we don't know how much power will be remaining for the CELL to utilize after being used for so many other non-graphical tasks.

One thing that has me encouraged is that I saw a trailer of Ted Price from Insomniac games stating that they were assigning different SPE's for different tasks. He said they were using a few for physics, one for sound, one for lighting, and so fourth. However, from what I have read in most cases that's probably the least efficent way to get the most from the CELL. The most efficent way is to break up each of those processes into perhaps dozens of tiny threads that will stream from SPE to SPE. When one SPE finishes a tiny part of a task then it will automatically ask for another, and all the SPE's stay busy.

If they are not utilizing advanced programming methods such as that yet for a GREAT looking game like RFOM then just imagine when they really start diving into the CELL.

Wouldn't that constant streaming generate context switching? I mean transferring data back and forth doesn't usually come free. I'm not sure this applies to the cell architecture, though.

Having each SPE handle its own data/buffers does seem optimal to me, at first glance.
 
There is a penalty for context switches, but from what I remember it's not too high and the cost of not performing them (and having SPE's that remain idle some of the time) can be even more costly.

If you know for a fact that a certain SPE is going to be utilized extensively and consistantly then perhaps reserving one for a specific task would be wise. For example, if you knew the sound in your game was so high quality that it would consistantly use a large portion of a SPE's processing power. But from what I have read (I'm not an expert in this) from a variety of sources it's usually more efficent to create tons of threads and have them streaming around the SPE's so you don't waste processing power by having SPE's sitting around idle.
 
I know one site that made this claim, but there is absolutely no evidence or even a source for this. And even if it was like that the 360 version is far more advanced in development, due to the predecessor...

COD3 is being developed by Treyarch, unlike COD2 which was done by Infinity Ward. And even though the two companies are part of Activision they do not share codebases or art assets (afaik).
Having said that, I saw COD3 for Xbox360 recently and it looks fantastic and as a matter of fact it does run at 60fps. The PS3 version is still being worked on and unfortunately I don't have reliable information about its frame rate.
 
There is a penalty for context switches, but from what I remember it's not too high and the cost of not performing them (and having SPE's that remain idle some of the time) can be even more costly.

If you know for a fact that a certain SPE is going to be utilized extensively and consistantly then perhaps reserving one for a specific task would be wise. For example, if you knew the sound in your game was so high quality that it would consistantly use a large portion of a SPE's processing power. But from what I have read (I'm not an expert in this) from a variety of sources it's usually more efficent to create tons of threads and have them streaming around the SPE's so you don't waste processing power by having SPE's sitting around idle.

While I can tell you - from personal experience - that context switching is very costly, I believe your information is sound.

The reason is that due to the peculiarities of game design and the architecture ofthe cell, developers struggle to actually use all the CPU power available to them. Simply because, as discussed here many imes, it's actually a challenge to develop multithreaded games.

Personally, however, I'd imagine some lockless 1 producer n consumers multithreading design, where the SPEs have specific tasks (as long the game in question allows it) would probably be optional.
 
That's where we differ in opinion. You count Cell as a 'quirk' in PS3 that'll make something a bit easier or what have you. I count Cell as a very strong component for performing tasks that XB360 hasn't got the processing hardware to match. I don't think that every game on PS3 can be ported to XB360 with the same quality, just with more time and effort spent to get there (and vice versa). There will be things on one platform unique to that platform that time and effort won't be able to add to the other one.

Especially so, since I think these are two very closely matched boxes.

There's nothing near the Xbox-Ps2 gap this time, imo, at least, so far, apparantly.

Throw in the weird EDRam on 360..that might be hard to duplicate..the machines are pretty dissimilar, in some ways, the other biggie being Cell.

So we might see, most ports being cut, simply depending on which is the lead platform..

btw, dont know if it has mentioned, but a lot of previews have noted or hinted the 360 version of COD3 looks better (whatever that means), Matt C said it in the newest ign podcast most explicitly, so the entire premise of this thread seems tenous..
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Glass pipe
 
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