Why More Companies Don't Contribute To X.Org

[RobbieAB]

Throwing more general purpose cpu's against a specialized solution is always going to be a less efficient solution. It's not like those specialized solutions are going to sit on their asses and not progress while general purpose solutions advance. Don't forget that for those high performance groups "good enough" maybe ok for your general user but "good enough" rarely is a phrase heard from demanding users as performance is usually the determining factor.

Of course. However, even though general purpose computers can't get close to the floating point performance of dedicated FPU systems, we still don't see specialist FPU chips anymore. (Ok, I know there is one system out there that is a specialist FP system...)

I'm not saying that the specialised chips won't remain more efficient, just that they will become more and more niche, to the point where though they have an efficiency edge, they will be so expensive that the mass market CPU will offer the same performance for less cash.

What is the difference between a GPU with a CPU stuck on the side, and a CPU with a GPU stuck on the side? GPGPU? It's a CPU if it's the main chip in the box...

[TemplarGR]

Throwing more general purpose cpu's against a specialized solution is always going to be a less efficient solution. It's not like those specialized solutions are going to sit on their asses and not progress while general purpose solutions advance. Don't forget that for those high performance groups "good enough" maybe ok for your general user but "good enough" rarely is a phrase heard from demanding users as performance is usually the determining factor.

You forget one thing:

Gpu power progresses far more rapidly than Cpu power.

We cannot increase the mhz and/or core count much. Of course, other improvements could increase the ipc, but in general, with each processing node from now on, cpu performance increases only for about 10-20% while gpu performance increases 100%. It is far more easier to increase gpu performance at this point.

Eventually we will reach a point where the ratio of CPU/GPU performance inside an APU, will reach a convient number, where it will be better to simply use more APUs than using discreet gpus.

[deanjo]

You forget one thing:

Gpu power progresses far more rapidly than Cpu power.

I'm not forgetting anything, I've already said that specialized solutions aren't going to sit on their asses while general purpose CPU's continue on with development.

We cannot increase the mhz and/or core count much. Of course, other improvements could increase the ipc, but in general, with each processing node from now on, cpu performance increases only for about 10-20% while gpu performance increases 100%. It is far more easier to increase gpu performance at this point.

Which is why I said that a general purpose CPU is not the solution for the high performance crowd.

Eventually we will reach a point where the ratio of CPU/GPU performance inside an APU, will reach a convient number, where it will be better to simply use more APUs than using discreet gpus.

IMHO, with the HPC crowd especially, the CPU will, more or less, become just merely another component on the board to handle delegation of computing to the various discreet devices and will become nothing more then an extension of motherboard chipsets.

[TemplarGR]

I'm not forgetting anything, I've already said that specialized solutions aren't going to sit on their asses while general purpose CPU's continue on with development.

No, you don't get it(yet).

Let me explain:

1) You think specialized vs general purpose are some kind of rivals. They are not. Intel and AMD from now on(with the exception of the first generation Bulldozer) will release only APUs. You will not be able to buy single cpus anymore, forget it. That's it. There is no antagonism between the two. They will cooperate *on-die*.

2) Since cpus cannot advance faster anymore, and squizing more cores in a die reaches diminishing returns, the solution will be the combination of cpu+ gpu. Cpu will act kind of a coordinator, while the bulk of heavy calculations will happen on the gpu side.This will happen both for graphics and gpgpu.

3) As the lithography advances, and transistors shrink, gpu will cover more and more of the APU die. As i said, it makes no sense putting more cpu cores there. You have to make something out of those transistors, and this something is a bigger gpu... Eventually, we will reach a point where a cpu could be 1/4 of the gpu part, or less...

When we reach this point, it will make far more sense to simply put more APUS inside a PC for increased performance. It will make no sense using GPUs alone. Only NVIDIA currently lacks an APU solution, and if it not solves this soon, NVIDIA will disappear.

Of course, for the gpgpu part, we need better OpenCL support, but be patient, it will come from both Intel and AMD...

[deanjo]

When we reach this point, it will make far more sense to simply put more APUS inside a PC for increased performance.

This is where I disagree, if the need is not there for more general purpose power there is absolutely no reason to include it.

[RobbieAB]

This is where I disagree, if the need is not there for more general purpose power there is absolutely no reason to include it.

So why bother putting in a specialised GENERAL PURPOSE GPU?

[TemplarGR]

This is where I disagree, if the need is not there for more general purpose power there is absolutely no reason to include it.

You are right. Ideally, gpu should never become extinct.

Where you are wrong, is that not all solutions in computing are ideal, in absolute terms. Sometimes we sacrifice some efficiency if it makes economical and/or programming sense.

When the bulk of gpus sold are on die, and software begins to become optimized for them, instead of discreet gpus, it will make more sense for AMD to drop discreet gpus and concentrate on APUs. If one needs more power, will buy more APUs It will not be more efficient than buying pure gpus, but AMD will not keep designing pure gpus if it makes little economic gain, while it can simply sell more APUs instead. Intel for obvious reasons(lack of discreet gpus) will do the same.

[deanjo]

So why bother putting in a specialised GENERAL PURPOSE GPU?

Since when has there been such a device? If a GPU was to be doing general purpose duties it would more then likely doing it through emulation given that the GPU had enough headroom to carry out those lighter demanding tasks.

[RobbieAB]

Since when has there been such a device? If a GPU was to be doing general purpose duties it would more then likely doing it through emulation given that the GPU had enough headroom to carry out those lighter demanding tasks.

Since nVidia started CUDA, ATI started stream processing, openCL... These are ALL aiming to harness the considerable power of the GPU at general purpose floating point operations. No current GPU is specialised "graphics hardware", they are general purpose floating point SIMD cores with all the magic done in the drivers.

And you know this at least as well as I do!

[jakubo]

it kinda does sound to me like "its not performing very good. lets put it in the kernel..." (just recalling the attempt to get dbus in kernel. what has become out of it by the way? systemd seems to use dbus as well. to some point...)
what will this developement be meaning for the kernel? will it become any different?