Pondering The Top Technical Innovations of the Playstation 4

[Cyan]

If the 8gb was dedicated to the GPU only, where would the OS be? Really now.

Unified memory is now the future, started with 360 and now both PS4 and Wii U use it

It certainly looks like it was... I thought that would be true since years ago, and if you look at the PS3 hardware, it isn't interrelated with the PS4 at all, which has been created with an unified memory system in mind.

In general terms everything is heading in that direction, well...except Durango. If Durango is successful then other companies might begin exploring that path, who knows. Life is chaotic, such is the world in which we live.

If you look at Sony's past and future, they have done a lot of different things. Durango is some kind of PS2, hardware wise, PS3 was also heavily customized, although to a lesser extent, and now PS4 has some in-house customizations seamlessly integrated in the unified memory sustem, but Sony could make a PS2 like console when PS5 comes out.

Nothing set in stone, but I am not sure sometimes what the future holds.

 

[patsu]

It is not uncommon for technologies to come full circle as researchers refine old tricks.

 

[Bagel seed]

I'm sure I'm missing the obvious but WPC?

Should be Work Per Clock.

 

[babcat]

Here is a little bit of information about the modifications made to the PS4 GPU.

http://forum.beyond3d.com/showpost.php?p=1712819&postcount=1188

I'm hearing that PS4 GCN has 8 ACE's, each capable of running 8 CL's each. I believe Tahiti is 2 per ACE, 2 ACE's.

How does this improve performance in the GPU?

Slide number 5 talks about them.

http://www.highperformancegraphics.org/previous/www_2011/media/Hot3D/HPG2011_Hot3D_AMD.pdf

 

[3dilettante]

The queues are how the system is able to request work from the GPU, and the ACEs are what are in charge of evaluating commands, allocating resources, and starting and tracking execution.

Multiple jobs can share the GPU without having to wait in line as long for their commands to be processed, and the GPU can fill up its CU array with multiple small jobs and still get good utilization.

 

[Bagel seed]

Sauce de spécialité? Mmm.

 

[3dilettante]

It's a bigger number of queues. The GCN architecture allows the number of compute pipelines to scale freely, and current GCN products have multiple queues, just not as many.

It's something that becomes increasingly helpful the more disparate jobs are added to the GPU, so I'm not sure it's special for Orbis. That it was put into a GCN ISA document means the PC is going to see it as well, at the very least.

 

[patsu]

What is the relationship and ratio between the ACEs and the DMA units ?

 

[3dilettante]

I haven't seen any data that indicates there's any significant relationship.

The ACEs can process various commands and set up kernel context, some of which might at some point involve a DMA transfer, but so does a lot of functionality that needs data traffic to or from host memory.
I don't have the expertise to say what that amounts to.

The DMA engines in GPUs are described as being more tied to the PCIe bus, one DMA engine for each direction on the bus.

 

[joesiv]

Just curiosity...the 8GB is system ram or dedicated to the GPU only?

The GPU is connected to the CPU (on the same die), what is the GPU's is the CPU's. This is how APU's work.

It's actually almost easier to think of the PS4 as a Graphics card, with the CPU embedded in the GPU; since it uses Graphics type memory.

 

[Arwin]

Yes. I wonder if you can see a render pipeline as a flow of data that 18CUs and 8 Jaguar cores can work on, branching off jobs to whichever is more suitable to the task?

 

[MrFox]

Unified memory is now the future, started with 360 and now both PS4 and Wii U use it

Amiga was Unified Memory in 1985.

(Achievement unlocked! Proclaim the superiority of Amiga 100 times in general conversation within the 20 years time limit)

 

[Gubbi]

Amiga was Unified Memory in 1985.

(Achievement unlocked! Proclaim the superiority of Amiga 100 times in general conversation within the 20 years time limit)

No it wasn't.

You had chip RAM and fast RAM

Cheers

 

[MrFox]

No it wasn't.

You had chip RAM and fast RAM

Cheers

Memory extensions don't count! All Amiga were 100% chip ram as long as you didn't upgrade the ram beyond what your chipset supports. Some games didn't work if you had any fast ram present, because they assumed all the available memory space was UMA and they could put sounds and bitmaps anywhere they wanted.

 

[Davros]

Related : In an apu how is the cpu connected to the gpu, is there an on chip pci-e bus or something different ?

 

[SenjutsuSage]

It certainly looks like it was... I thought that would be true since years ago, and if you look at the PS3 hardware, it isn't interrelated with the PS4 at all, which has been created with an unified memory system in mind.

In general terms everything is heading in that direction, well...except Durango. If Durango is successful then other companies might begin exploring that path, who knows. Life is chaotic, such is the world in which we live.

If you look at Sony's past and future, they have done a lot of different things. Durango is some kind of PS2, hardware wise, PS3 was also heavily customized, although to a lesser extent, and now PS4 has some in-house customizations seamlessly integrated in the unified memory sustem, but Sony could make a PS2 like console when PS5 comes out.

Nothing set in stone, but I am not sure sometimes what the future holds.

I think it might be best to see the fruits of Microsoft's labor first. I suspect that design decisions that are now criticized will begin to be looked at in a new light.

 

[patsu]

I haven't seen any data that indicates there's any significant relationship.

The ACEs can process various commands and set up kernel context, some of which might at some point involve a DMA transfer, but so does a lot of functionality that needs data traffic to or from host memory.
I don't have the expertise to say what that amounts to.

The DMA engines in GPUs are described as being more tied to the PCIe bus, one DMA engine for each direction on the bus.

From the VGLeaks article, it seems that the CPU could set memory policies and potentially issue DMA requests too ? I am not sure if I read that diagram correctly.

EDIT: ok... GCN DMA could access pageable memory.

 

[babcat]

Now I am reading that the PS3 may have a vector unit in addition to the GPU, CPU, and OS chip.

If the PS3 had a small, cut down cell chip that could help the GPU that would be significant.

 

[Shifty Geezer]

Let's not discuss random (and extremely unlikely) rumours here; there's already a thread for that. This thread should only discuss 'knowns'.