rumor ps4 might use ps3 cell chip

[smallflyingtaco]

goddog said:

smallflyingtaco said:

goddog said:

it will be interesting, the powerpc chip that ms uses is easier to scale in terms of power, but with that comes heat, the major problem with that series of powerpc, i could see it going uniform quad core, or even different changes like that, since none of that would effect coding, but we just havent seen any new info from ibm on this series of chip, something the publish quite regularly along with the cell updates, and the joint project with motorola (now freescale) that produced the GC/wii chip

They can both easily jump to the high performance POWER line of processors, it includes the entire old PowerPC instruction set, but they are going to cost a lot.  Power7 is an 8-core and is supposed to be out by 2010. 

 

 

true, but power7 would not work with the current power4 dirvitive that is in the 360, or the  cell power arch, the instruction sets are not the same, and the power 8 was additional features that are useless to both of them, the 360 uses  gutted power4, the wii uses a power2 or 3  derivative.  changing arch would hurt either console as seen with the wii keeping the same arch helps in cost, and developer ease.... cell is the more interesting of the two as the 360s chip is already very traditional power pc just stripped down for gaming. the cell if they were to rework it which it looks like they will not, could be made more programer friendly however that would be at the cost of programing assets made for the current cell. if they jus advance it, there will be some change to the arch and dev assets but they may still be useful. though it may just be an issue of cost, and bringing the next ocnsole in where it can turn a proffit at a cost of say 399 at launch or a small loss at 299

I have yet to see anything on POWER8 so your ahead of me there.  Even if MS is using a derivative set of instructions it does not mean it will not be compatible with the POWER7, as we would have to know if they have more instructions or a subset of the POWER7 instruction set.  The same with Broadway.  If they have added instructions then it would rule out an off the shelf solution without some middleware to deal with it for backwards compatibility.  As for developer ease the instruction set differences between them should be easy to hide from developers by the compiler as they will not change a lot in architecture by replacing the CPU with a standard IBM CPU.

The CELL is not going to be simple in its current form.  That the various cores are so different that you have to know what goes where.  Getting around that will not be easy as some of the elements of it that are so powerful are tied to that.  The SIMD SPEs let it do a lot of certain types of work but that they are SIMD while the the PPE is a fused multiply-add processor, it can solve 2 y=ax+b type problems per cycle, keeps this complex.  Removing the SPEs would hurt it in graphics programming, and in scientific programming, but shifting the PPE would make life harder for regular programming type needs.  Probably from a development standpoint doing something like is done on Roadrunner and adding a completely secondary powerful general purpose processor would make life easiest.

Cost I have no clue on.  The problem of dealing with these makes life hard on the console makers as they need to sell a lot to get scale based discounts.  The easiest solution would be for them to try and do what Sony aimed to do, use a processor that was supposed to be used in a lot of other things.  The problem though is consoles are frozen in time while everything else moves on and you might be wrong to start with.  If they all used the same processor they could perhaps help this but that would probably hurt their marketing and encourage even more multiplatforming.