So, 1 PE after-all or is this just for GDC 2005 ?

They are fundamentally different but share some parts of their architecture. If even that.

 

I don't remember reading anything about IBM having trouble with the customizations done for the Xenon CPU.

 

A couple of pages back Deano had this to say:

That was the first I've heard of it too. Interesting info.

Tommy McClain

 

Oh no! Vince will need to find a new crusade.

Seriously does IBM have more interest in one design winning (for their own use) over another? Specifically, since the IP involved with both designs are held by multiple parties does any agreement for cross licensing make one design a preferable foundation for IBM's own business outside of the console market?

 

That roadmap slide as of May 2004 shows 3 lines, and the 970 custom processor line in the middle is captioned as "Desktop/Game". So, if the PPC 300 65nm embedded core (I doubt its existence though) is a core for the Cell PU, it seems at least one of other consoles use other cores in the 970 line (in the same line there's 750cx for Gekko).

 

Oh, one more thing about Power. In the Cell Processor feature set disclosed in the first press release, it contains "Supports multiple operating systems". It means it has the hardware virtualization feature (Micro-Partitioning/IBM Virtualization Engine) which is currently only seen in IBM server line processors (POWER5). Consequently, if the Cell PU is something derived from PPC970 or PPC440, then it has to be heavily modified.

Microsoft surely doesn't want this feature in Xenon, for their OS is Windows anyway

 

Well, I don't know the reason why Xenon is thought to use a PowerPC 3xx derivate if it's something developed after PPC 440. Can it be clocked at 3.5Ghz+? Also, scalability requirement for Xenon CPU looks like lower than Cell, so using a tiny core seems nothing more than the cost reason. Is the lowest power usage/heat really required for a console?

Btw, "basically the same people working on both"... I think you mean M. Gschwind on "Contributions to IBM's family of state-of-the-art processors", but who other do you mean?

 

Oh of course - the S|APUs are pretty certainly a completely new ISA - I wasn't implying paralels between whole architectures, or even less - programming models (which look to be very different at the moment), just the PPCs cores which both of them use.

And can it be clocked to 4Ghz+?
Just because both Xenon cpu and Cell PUs could be derived from same core, it doesn't mean that core must be an existing PPC derivate, does it?
Clean sheet design and all?

With 3 PPC cores, those 'super' VMX units with two 128*128 register files each, 1MB of L2 cache, L1 caches, DMA controllers etc. you're not exactly talking about a small die you know.
And we don't know yet how 'tiny' the PPC core is or isn't

 

It does bear noting that even if the two CPU's are derived from the same core, they wouldn't necessarilly have the same functionality.

Would it make sense for a Cell PU to have a super VMX component? I'd say no since it's clearly designed to offload computations to the A/SPU's.

 

Definately agree with that - that's why I used the word 'derived'. The differences in memory subsystem and other things would warrant quite a number of different customizations for each part also.

 

For those 'super' VMX units, they can go with the alternative implementation described in the recent patent - as at least one core is always a 'host' CPU core if they don't rely on threads too much, it can omit its VMX unit.

Anyway, the 1st-gen Cell may have a different PU from that in the Broadband Engine or other variations of Cell, who knows

 

Excellent. What an interesting and informative thread It's really amazing how much more infomative a thread can be without certain people insulting everyone.

Bravo. So what do all of you think about porting between consoles. will the simularities (as small as they may be) assist in writting code game code that doesn't need to be rewritten each time? Or will it be basically about as challenging as it currently is.

 

Sony PS3 = 1 PU

Sony Stereo = 1 PU

Sony Toaster = 1 PU

PS3 to optical cable (bi-directional) -< Stereo & toaster = 3 PU = CELL????????


These are things that go through peoples heads - speculation speculation speculation.

Sony needs to release more info, just like Team Ninja says.

 

I think it's going to get MUCH harder. I think we will see more exclusives this next generations.

The mutliplatform games will look poor compared to first party games even more than they do now.

I think its true that game prices are going to go up.

 

I think we'll see less exclusives FWIW. But this has more to do with development cost than ease of porting.

Aguably something written to run efficiently on a Cell like architecture could probably be made to run efficiently on Xenon. Since you've commited to data locality and a host of other things that reduce the stress on the memory system. Of course that doesn't account for any performance delta between the two or running vertex shaderts in different places or what ever. It also potentially wouldn't be the most efficient way to do an operation on Xenon.

Flipping that agument, something written to run optimally on Xenon could potentially be a real bear to port to a Cell like architecture. If you assume a shared memory model, it's going to be potentially difficult to port to a segmented one. One example might be a game that relies heavilly on a scripting language and distribute the scripts across multiple processors on Xenon. It may not be possible to do that on a Cell like architecture, because the combination of the interpreter and the associated global structures would blow the limited APU/SPU code space.

Personally I think for the most part you'll see people use the parallelism for the easy stuff, better graphics for the most part, and physics when they have a 3rd party library that will deal with it for them. The majority of the game code will probably continue to be single threaded, but I could just be being jaded.

 

How similar are the "super VMX" units in each Xenon CPU core and the APUs in Cell likely to be? Is there any chance they could share some technology?