Digital Foundry: next-gen PlayStation and Xbox to use AMD's 8-core CPU and Radeon HD

[Kenmitch]

The idea is to write code around a absolutely exact spec

This is why it doesn't matter too much what the underlying hardware is gonna be. If the leaks are true I'm sure it's already proven that the hardware in question is more than capable of fullfilling the GOALS of both MS and Sony.

Consoles are a set hardware base and don't run on a bloated OS with a decade of backwards compatability for 1000's of devices. The OS is optimized for the hardware in the console only! This equates to more getting done with less.

 

[Fx1]

i think the real problem here is an 8 core part doesnt exist. Jaguar seems to be a dual core and quad core part. That means either someone is full of [it] or there are likely to be 2 chips inside.

moving from 4 to 8 cores isnt simple as sticking them together on one die. It would be smarter to have a fast quad core inside than 8 underpowered CPU's which are stuck together in a 4+4 configuration. We are still looking at 50w for a 8 core CPU. at 50w you can go for a very fast quad core.

8 cores dont make any sense

Also the poor yield CPU's will be useless since who wants to use a broken 8 core chip?

If they stick to 4 core parts they can use efficiency with their current parts pipeline.

I expect Sony would rather have cheap CPU's than a custom one which costs more

No profanity in the tech forums. please
-ViRGE

 

[Kenmitch]

i think the real problem here is an 8 core part doesnt exist. Jaguar seems to be a dual core and quad core part. That means either someone is full of shit or there are likely to be 2 chips inside.

moving from 4 to 8 cores isnt simple as sticking them together on one die. It would be smarter to have a fast quad core inside than 8 underpowered CPU's which are stuck together in a 4+4 configuration. We are still looking at 50w for a 8 core CPU. at 50w you can go for a very fast quad core.

8 cores dont make any sense

Also the poor yield CPU's will be useless since who wants to use a broken 8 core chip?

If they stick to 4 core parts they can use efficiency with their current parts pipeline.

I expect Sony would rather have cheap CPU's than a custom one which costs more

Gonna be a custom design to meet specs/goal of the consoles. I wouldn't think it's gonna be a off the shelf sku.

I wouldn't blame who supplies the hardware for the next gen consoles for the potential performance or lack of....Just supplying what is asked for in the end.

 

[Zstream]

i think the real problem here is an 8 core part doesnt exist. Jaguar seems to be a dual core and quad core part. That means either someone is full of shit or there are likely to be 2 chips inside.

moving from 4 to 8 cores isnt simple as sticking them together on one die. It would be smarter to have a fast quad core inside than 8 underpowered CPU's which are stuck together in a 4+4 configuration. We are still looking at 50w for a 8 core CPU. at 50w you can go for a very fast quad core.

8 cores dont make any sense

Also the poor yield CPU's will be useless since who wants to use a broken 8 core chip?

If they stick to 4 core parts they can use efficiency with their current parts pipeline.

uhhh what?

Multiple cores makes very good sense when used properly. In fact, in consoles, with dedicated set hardware, being able to code on multiple cores is exactly what developers want to do. They don't want to deal with HT or some bastardized version of CMT (bulldozer). They want multiple cores with reproducible results.

This allows the device to have specialized code:

Core for audio processing if a seperate audio processor is not present.
Core for background processing, such as an input controller, kinect device etc...
Core for gui integration, such as Xbox live and any other wrapper needed.

Multiple cores left over to be load balanced for hard number crunching.

 

[Fx1]

Gonna be a custom design to meet specs/goal of the consoles. I wouldn't think it's gonna be a off the shelf sku.

I wouldn't blame who supplies the hardware for the next gen consoles for the potential performance or lack of....Just supplying what is asked for in the end.

Given how screwed sony got with the CELL CPU id expect Sony to take a different approach this time.

Wasted wafer is wasted wafer and if you make an 8 core part then if you get one bad core the whole CPU is wasted.

Even the Cell was a faulty version of its self with some bits turned off.

Maybe it is a 4+4 config with two chips on one die area like the Q6600 Intel CPU.

 

[Fx1]

uhhh what?

Multiple cores makes very good sense when used properly. In fact, in consoles, with dedicated set hardware, being able to code on multiple cores is exactly what developers want to do. They don't want to deal with HT or some bastardized version of CMT (bulldozer). They want multiple cores with reproducible results.

This allows the device to have specialized code:

Core for audio processing if a seperate audio processor is not present.
Core for background processing, such as an input controller, kinect device etc...
Core for gui integration, such as Xbox live and any other wrapper needed.

Multiple cores left over to be load balanced for hard number crunching.

Did you even read what i wrote. my comments were around the physical number of cores and not the threads.

 

[quest55720]

What choice is there for Sony if the steamroller is not ready for a fall 2013 console launch? I am sure they looked at the piledriver and decided against it for a reason. Intel was never in the game for any console. Intel loves its margins way to much to be in a console ever again. Also the console makers would rather own the IP and find a place to make it. Then get the cost savings of die shrinks intead of that money going into the pockets of intel. MS learned that lesson the hardway in the xbox 1.

 

[Zstream]

Did you even read what i wrote. my comments were around the physical number of cores and not the threads.

That's my point, threads are not cores.

 

[Fx1]

That's my point, threads are not cores.

You need to have threads to make use of cores or they sit idle

 

[Zstream]

You need to have threads to make use of cores or they sit idle

**OBTUSE**

Multiple smaller cores separated by task/s, assuming IPC performance is not terrible, is better than a single fast core with multiple threads. The only reason why people are on the single fast IPC core illusion is due to poor programming skills and API overhead.

 

[Fx1]

**OBTUSE**

Multiple smaller cores separated by task/s, assuming IPC performance is not terrible, is better than a single fast core with multiple threads. The only reason why people are on the single fast IPC core illusion is due to poor programming skills and API overhead.

i think you will find i am talking about Quad core CPU and not a single core.

Single cores are 1999 who even talks about a single core any more.

The problem with 8 slow cores is that you are limited by the speed of each core

not all workloads can be divided between 8 cores. I have yet to see a game take full advantage of 8 threads in a single game. BF3 can use 8 but it hardly does it with any elegance.

We are talking about a CPU up to 5ghz there too which has abundant power. 1.6ghz 8 core is going to be anaemic in comparison. Consoles are supposed to be more efficient but to be honest they do everything worse than every PC i have ever owned and even my TV does netflix better.

In this day there is no reason to go as low as 1.6ghz

 

[VulgarDisplay]

Why do people fail to realize that game developers suck at multithreading because they have not had good multithreaded hardware to code for. There will be growing pains on the new 8 core consoles but eventually they will figure out how to get the most out of the cores they have available.

If you follow some of the reasoning I've come across so far in this thread we would still be using single core single thread CPUs. If games only use 2-4 cores now it doesn't mean they cannot use more in the future.

 

[Fox5]

**OBTUSE**

Multiple smaller cores separated by task/s, assuming IPC performance is not terrible, is better than a single fast core with multiple threads. The only reason why people are on the single fast IPC core illusion is due to poor programming skills and API overhead.

I'd say it's the opposite, the advantage of more cores is due to poor programming skills.

A single core twice as fast will give more than double the performance of 2 cores half as fast. However, those two cores can each have dumb (or no) scheduling and run two applications at once with 100% cpu utilization, whereas a single core would need some kind of task slicing for interactivity.

 

[ShintaiDK]

Why do people fail to realize that game developers suck at multithreading because they have not had good multithreaded hardware to code for. There will be growing pains on the new 8 core consoles but eventually they will figure out how to get the most out of the cores they have available.

If you follow some of the reasoning I've come across so far in this thread we would still be using single core single thread CPUs. If games only use 2-4 cores now it doesn't mean they cannot use more in the future.

I would rather think its the nature of game coding, rather than the skills of the developers.

Some applications are simply in nature better suited for multithreading than others.

 

[Piroko]

Isn't AI-processing an almost perfect example for easy multithreading? Each bot/monster/whatever spawns an own thread and gets shifted to the core with lowest current load.

 

[Tuna-Fish]

Isn't AI-processing an almost perfect example for easy multithreading? Each bot/monster/whatever spawns an own thread and gets shifted to the core with lowest current load.

Only when they cannot do direct changes to the world and nothing touches it while they work. The easiest way to code AI is absolutely not parallelizable cross entities.

 

[Tuna-Fish]

Wasted wafer is wasted wafer and if you make an 8 core part then if you get one bad core the whole CPU is wasted.

That's why you disable one core of 8 in all chips so that you can salvage most faulty chips. The same will happen with the CUs of the GPU, and ways of the cache.

And there will not be multiple cpu chips in the console. In fact, in durango there will be one chip, which is an APU. As for "Jaguar 8-core does not exist", Jaguar is integrated as clusters of 4 cores+L2. More than one such cluster can be integrated into a single chip by using a cache-coherent interconnect that attaches to the L2.

 

[Piroko]

Perhaps, but at the same time this creates very noticeable decision patterns. I have yet to find a game where the AI is too random to exploit their patterns. With decoupled pathfinding and decision making algorithms one could simulate a much more dynamic AI.

 

[Haserath]

Source scales to 8 cores easily. Now imagine those developers on this.

 

[itsmydamnation]

few things,

Moderns Game engines now use job/task based systems, they are no longer serial and inherently multithreaded. If you only see a few threads in PC games thats because of lowest common denominator PC specs.

Lots of game code very neatly fits into 4 wide FP vectors ( 128bit) but not 8 (256bit)

Xenons is already 6 incredibly weak threads

who said anything about Jaguar being "slow", Jaguar will offer IPC per thread around 6 times that of Xenons and those are "better quality" instructions ( RISC vs CISC)

Bobcat doesn't look that great these days because of 64bit FPU, this doubles latency(of the execution) for 128bit SSE2/3/4 and halves throughput compared to 128bit FPU ALUs that are in Jaguar.

And there will not be multiple cpu chips in the console. In fact, in durango there will be one chip, which is an APU. As for "Jaguar 8-core does not exist", Jaguar is integrated as clusters of 4 cores+L2. More than one such cluster can be integrated into a single chip by using a cache-coherent interconnect that attaches to the L2.

just to back this up.

During last years jaguar presentation for hotchips it was stated that the 4 cores and L2 are a compute unit, that the L1/L2 is completely inclusive(bobcat/bulldozer dont do this) and number of Compute units in a SOC was a SOC level decision.

 

[Fx1]

Source scales to 8 cores easily. Now imagine those developers on this.

id rather never see the source engine in a game ever again. It looks like crap

 

[Subyman]

Why do people fail to realize that game developers suck at multithreading because they have not had good multithreaded hardware to code for. There will be growing pains on the new 8 core consoles but eventually they will figure out how to get the most out of the cores they have available.

If you follow some of the reasoning I've come across so far in this thread we would still be using single core single thread CPUs. If games only use 2-4 cores now it doesn't mean they cannot use more in the future.

Most game developers use tools to create their games. Hardly any build a game from the foundation up. It is MS, Sony, and Nintendo that need to provide the correct tools to properly implement the full potential of their system. Engine builders dig deep into code base, but what people normally consider a "game developer" spend their time using established methods and functions.

I think what you mean is that the game utility/engine/sdk providers need to step up quickly when a new console is launched, not the game developers. And it certainly isn't about "sucking", its about not having the tools available to create what the marketing is pushing.

 

[2is]

id rather never see the source engine in a game ever again. It looks like crap

Somewhat agree, the engine is quite dated. Who cares if it's been optimized over the years to scale to 8 cores when you only need 2 to get 60+ fps

 

[Fox5]

Isn't AI-processing an almost perfect example for easy multithreading? Each bot/monster/whatever spawns an own thread and gets shifted to the core with lowest current load.

AI doesn't work as a shared nothing design, although spawning a thread for each entity might be ok in a cpu design with a large shared cache, such as the core 2 duo. (the shared L3 cache might be too slow)

I think AMD Jaguar does have shared L2 caches though.

 

[Haserath]

id rather never see the source engine in a game ever again. It looks like crap

That's due to Valve's stance on 'good enough'.