Lonely1 said:
But the power of a CPU isn't solely determined by the numbers of cores. If there anything planed with ARM that can compete with years old PC parts? Smartphones might have quadcores next year, but they will still be considerably behind 5 year old Core 2 Duo's in performance.
Note the "Core 2 Duo" level. Sure, ARM A9s are not as powerful as x86 CPUs but they're not completely out of picture either. Plus you have to consider that ARMs in smartphones operate under completely different power and heat dissipation requirements than would be avialable in a console's box.
Plus just how much GP processing power does a console need?
ARM is used in supercomputers now, to feed data to GPU compute clusters. Thus having a good GPU may mean that you don't need as strong of a CPU anymore.
DCKing said:
You should've checked out the Wii U thread. My theory is they used an RV770 because it has a GDDR3 memory controller, and it has the power they wanted. It needed a GDDR3 memory controller because it seems they're using the Xbox 360 CPU in devkits as well.
RV770 was the first one to use GDDR5. Every Radeon since X800 (R420) have a GDDR3 controller. Current Radeons can use GDDR3 too. They could've easily use Cayman in their devkits but ut seems that they're using RV770. Why? I see the only explanation: Wii U GPU will be on RV770 level features wise.
DCKing said:
More cores doesn't mean more power. There's a point at which it is not useful anymore (
Amdahl's Law) and there aren't any more tasks to thread out. Fast multicore POWER7 > many simple parallel cores. It simply doesn't get faster than POWER7 at this point.
In a console environment 8 ARM cores would be preferable to 4 POWER7 cores while being much much simplier. This was already shown this gen with Cell and XCPU. Btw, ARM A15 is an OoOE design.
DCKing said:
Every chip is customized. I agree. No chip in the history of gaming has not had its roots in some other application. Cell (and PPE) came as close as you get as something new, and that didn't even turn out that great. At the moment, there's nothing in the works that I know of that rivals high-end x86 and POWER7 in performance. That was not the case last gen.
Cell is the only reason why PS3 is technically ahead of competition at the moment. It's a great example of many simplier and harder to program cores winning against several more complex but easier to program for cores.
Going into next generation though one thing should be considered: most of what Cell SPEs are doing should now be done on GPU (via CUDA/OpenCL). And thus it now may be better to use smaller (meaning cheaper) CPU cores in a not-so-high numbers (2 POWER7, 6 PPCs or 8 ARM A15s) while shifting SPEs workload to a next gen GPU (AMD's GCN/Tahiti, NV's Kepler). That's the main reason why going with small numbers of OoOE cores may well be an option for Xb3/PS4.
DCKing said:
POWER7 is similar to, but not backwards compatible with the old PowerPC G3 architecture used in Wii and GC. The CPU in the Wii/GC had some customizations that would need to be ported over.
I'm quite sure that this can either be added to POWER7 relatively simply or emulated without much perfomance loss.
DCKing said:
Furthermore, the GameCube and Wii GPUs have a peculiar shading solution that is not easy to emulate.
Nothing peculiar about it, they're both fixed function GPUs (pre-DX8 era). Anything done in fixed function can be run on current unified shaders hardware.
DCKing said:
Then there's some fast timed caches, microcode here and there, as well as a funky sound system. I actually think there's no way Nintendo is going for software emulation. Less than 100% BC is unacceptable to them, and I think for many of the Wii buyers as well.
Well, including Wii's hardware is an option but I'd really prefer s/w emulation. It just allows you to do much more with the old code than the old h/w has ever allowed.
