That was a split-memory pool, as Cerny said. Main memory and eDRAM means copying still had to be done.Why? The 360 had unified memory plus shed loads of bandwidth to the eDRAM and a GPU architecture that was not only well beyond the common DX9 spec when it launched but in some ways beyond DX10 to say nothing of it sporting bleeding edge performance.
We all know pushing hardware is not a PC strong suit. If it was, this wouldn't even be a conversation worth having. Just because PC has the hardware doesn't mean it will get used. This has been demonstrated generation after generation. Are you expecting that to change all of a sudden? That's what would have to happen, in order for your statement about having several possible answers in the PC, for it to matter.PS4 has what? Unified memory, a standard DX11 GPU, a performance target around the PC upper mid range and some GPGPU enhancements for which there are several possible answers to in the PC space (e.g. far more powerful CPU's like Haswell or utilising APU's like Kaveri).
How can it seem far fetched, when DirectX 11 doesn't even see all the functionality of GPUs? You seem to believe that DirectX 11 is not extremely wasteful and pushes GPUs to it's max. Neither one of those beliefs are true.Add to that the general PC like architecture of the new consoles and your expectations of greater console effectiveness for a given performance level over last generation seems a little far fetched.
Are you saying DirectX 11 sees GCN functionality to exploit it or that this is automatically recognized? Also, the GCN, in the PS4, is much more functional than what's currently in PCs. That would be an architecture advantage. Please don't try to dismiss it.As AndyTX said, no this is not the case. Aside from anything else we've already been told by Exophase (and other developers here) than GCN and possibility even older architectures can already switch between graphics and compute on the fly and do not need to stop one to start the other.
2 ACEs are almost as good as 8 ACEs with 64 total cues? That's what you're saying?The GPGPU enhancements of PS4 and Durango will really come into play where those jobs are highly sensitive to latency, but for the types of GPGPU stuff we see today effecting graphics only - which includes TressFX - there's no reason to expect PS4 to be significantly better than a regular discrete GCN based system.
Evidence that the article I presented is not pertaining to DirectX 11, even though it was written almost 2 years after DirectX 11 emerged? And, evidence that the graph, done by a forum member's study, was not accurate (DirectX 11 vs OpenGL)? That graph looked pretty telling to me. Plus, libGCM is even lower level than OpenGL.Evidence of what? DX11 having less overhead than DX9? It's common knowledge, a quick google will reveal dozens of different sources for that information. Your very own link posted earlier in this thread is one of them.
Most amateur and journalism photography simply uses the smallest stop you can get away with for the speed of exposure ... we expect clarity, we tolerate technical limitations.But in photography of the real world, which is what most people are comparing screen visuals to, blur and the like makes it more realistic.
That was a split-memory pool, as Cerny said. Main memory and eDRAM means copying still had to be done.
We all know pushing hardware is not a PC strong suit. If it was, this wouldn't even be a conversation worth having. Just because PC has the hardware doesn't mean it will get used. This has been demonstrated generation after generation. Are you expecting that to change all of a sudden? That's what would have to happen, in order for your statement about having several possible answers in the PC, for it to matter.
How can it seem far fetched, when DirectX 11 doesn't even see all the functionality of GPUs? You seem to believe that DirectX 11 is not extremely wasteful and pushes GPUs to it's max. Neither one of those beliefs are true.
Are you saying DirectX 11 sees GCN functionality to exploit it or that this is automatically recognized? Also, the GCN, in the PS4, is much more functional than what's currently in PCs. That would be an architecture advantage. Please don't try to dismiss it.
2 ACEs are almost as good as 8 ACEs with 64 total cues? That's what you're saying?
Evidence that the article I presented is not pertaining to DirectX 11, even though it was written almost 2 years after DirectX 11 emerged. And, evidence that the graph, done by a forum member's study, was not accurate (DirectX 11 vs OpenGL). That graph looked pretty telling to me. Plus, libGCM is even lower level than OpenGL.
we need move/kinect to track eye movement and feed it into the DOF shaders
We all know pushing hardware is not a PC strong suit. If it was, this wouldn't even be a conversation worth having. Just because PC has the hardware doesn't mean it will get used. This has been demonstrated generation after generation. Are you expecting that to change all of a sudden? That's what would have to happen, in order for your statement about having several possible answers in the PC, for it to matter.
2 ACEs are almost as good as 8 ACEs with 64 total cues? That's what you're saying?
Evidence that the article I presented is not pertaining to DirectX 11, even though it was written almost 2 years after DirectX 11 emerged. And, evidence that the graph, done by a forum member's study, was not accurate (DirectX 11 vs OpenGL). That graph looked pretty telling to me. Plus, libGCM is even lower level than OpenGL.
www.gamertechtv.com/2010/directx11-games-for-2010-and-2011/2 years ago how many games were coded for dx11?
Does it have to be 4x as good for you and others to recognize it as "significant" or an architectural advantage?8 aces does not mean anything like 4 times as good as 2 aces. They allow more in flight threads which will increase efficiency which will increase performance, but having more CU's like a PC reaches that goal just in a different way. Consoles don't have the power budget so they target efficiency, this is less necessary on PC. However if there is a significant advantage for PC parts with more ACE's we may well see that happen on future parts.
You can continue to use out of context quotes to reinforce your own opinion, but I don't doubt it will become quite apparent in short order that consoles will no longer be launching as machines at the pinnacle of performance. Power budgets and economics have caught up with them.
I'm suggesting exactly what I said. It's split-pool memory, like Durango is rumored to be. It sounds like you agree. Does the X360 not have cache, too? Would that not be an extra step? If it is, then it sounds like you agree with me.Are you suggesting that EDRAM was a disadvantage for the 360 compared to PCs of the same time period?
You always have to copy your data back to main memory. Ideally you do it in as large batches as possible. EDRAM facilitated this quite well on the 360.
Yes, you are effectively doing two copies, one to EDRAM, one to main ram - but then you could consider the same thing when using the caches. Redundant work isn't being done, which you seem to be suggesting (?).
Why would you say the amount of draw calls you mentioned to be silly for PC, when that would be a very low number for consoles? Are you saying PCs can't benefit greatly from 10K to 30K draw calls? Does this not give much greater artistic freedom for environments (as the article and Timothy Lottes said)?While it is obviously true that the PC platform has certain overheads (especially related to CPU usage for the driver layers, etc) in practise it doesn't really have a big impact on actual performance when GPU limited. The layers of abstraction typically have greatest impact on a subset of the rendering pipeline (API calls) - and if those layers aren't the bottleneck (which they usually aren't - unless you are being silly trying to perform 10s of thousands of draw calls per frame).
It still seems bad according to the article and Timothy Lottes. I think even Sebbi had something nasty to say about the overhead. That member comparison chart between DX11 and OpenGL looked pretty horrible, too. LibGCM is suppose to be that much better than OpenGL. I'm not talking about the difference between DX9 and DX11 draw call overhead. However, it WOULD be nice to see that data. I just don't think it will show up.Otherwise, the reasons console games are more heavily optimised is pretty simple (and in my opinion has nothing to do with the layers of abstraction). Simply that it *has* to run well on the target hardware and with fixed hardware you can devote more time to it - you can't and don't have to let the user dial down settings. With that said, DX10 and DX11 alleviate a lot of the compatibility work required when building PC games of old - time that can be put into optimisation.
Are you saying there is nothing that can be done with libGCM/PSSL that can't be done with DX11? If something is wasteful on one platform, it's a chance for ground to be gained on the other. That would be my point. If you say that's not true, then I'll let it be.I'm not sure what your point is. Granted, there will be a subset of GPU features that are not directly exposed via DX (or GL) - however this doesn't mean the driver doesn't use them (why would they exist otherwise - hardware is built to DX11 spec, it would be wasteful to do otherwise?).
I'm basing the second statement on what I've already posted. If a PC can't do 30K draw calls on DX11, that's obviously wasteful. Timothy Lottes, the article and the B3D forum member's graph all say about the same thing. I put it all in my original post.What evidence are you basing the second statement on?
There is a good deal of anecdotal evidence to already suggest your claim is bogus; performance throttling being a simple example, and synthetic tests commonly hitting theoretical peak numbers. I'm not a DX11 expert so I'm not going to say you are wrong, but I'd like some evidence.
Does something have to be new to be efficient or functional to some people ("there is nothing new under the Sun")? What I don't understand is that if we don't know the real world implications of such a drastic increase in cues will due, why assume it's not very helpful? That seems worse than taking a direct correlation between the difference in the amount of cues. If based on a 4x increase, at least, then it would be based on math. I'm just saying it's an architectural improvement over what's currently available in PC hardware.Well, one would hope the graphics driver does (!).
We don't know much about the customizations to GCN in the PS4, other than the additional ACEs and cache bypass - which I wouldn't class as new functionality (more minor optimisations / extensions for a specific use case).
Anyone who knows the answer to that question would break their NDA if they answered.
The statement you are questioning (to me) implies a comparison of latency due to driver and abstraction overhead (not to mention potential latencies due to PCI-e data transfers etc), which I think we can be pretty confident is an area the PS4 can have a clear advantage (cache bypass, etc).
How this translates to realworld performance has yet to be seen - but I'd agree with pjb that it likely will only help with very low latency jobs.
It should've been a question mark instead of a period. I have corrected it. Thank you for pointing it out.Not sure what you mean here? It's not accurate but telling?
I want fact and not opinion. Is it an architectural advantage to have 8 ACEs instead of 2 ACEs? Is it an architectural advantage to have 64 cues instead of 16 cues? These answers should be fact and not opinion.
If you only mean to suggest that a console will outperform a 2TF PC, I don't think you will find much argument. The problem is when you try to suggest console hardware will punch twice its weight. Those days are gone. My year old PC will be running next gen titles with higher fps, resolution and AA.This have never been about the PS4 set up being equal to a Titan in hardware. It's about the PS4 being a lot more capable than similar PC hardware (due to software and architectural differences). Why are people tring to make it more than that?
I think Windows PCs could use the efficient software in consoles just as much or more than consoles could use the highest end hardware PCs could provide. We know that level of software performance won't/can't happen in the Windows PC environment, though. Developers must target lower GPU set-ups for profits. And, developers can't focus on one particular hardware set.I'm not sure how you justify the above statement. Clearly the power of current high end PC hardware goes either unused or used inefficiently because the (console derived) software doesn't require that power. Should the software change and start requiring higher performance, that performance will be used if it is available, whether or not it's in a PC. It's not difficult to max out a dual core CPU or entry level GPU in modern games and that will be no different next generation with higher specification hardware.
I agree, however aren't CUDA cores less flexible (switching between physics tasks and graphics)?If CPU compute requirements increase next genreation then there's no reason that more powerful PC CPU's will not be fully utilised in meeting those requirements. I'll grant you that using the IGP's of APU's as dedicated GPGPU processors is more questionable given that it would require some level of developer and/or vendor support but NV has certainly achieved this type of support with PhysX so there's no reason AMD couldn't achieve the same - at least in some flag ship titles where it most matters. Their HSA presentations certainly show that they want to push this as a usage scenario.
I would say the true diminishing returns scenario is in the graphics department and not with the ACEs. That, much like your statement, is just a guess.No, but there is certainly an element of diminishing returns to take account of. 2 ACEs with 16(?) queues is still a lot of scheduling capability for compute work on the GPU. How much benefit to you derive from scheduling more? Surely beyond this point you are getting to smaller tasks which would be just as well, or better run on a CPU with greater SIMD capability. Lets not lose sight of the fact that for every task you move from the CPU to the GPU via the ACE's you're using up CU FLOPs that could be spent of graphics. With only 18 CU's it might be worth considering just how much of the GPU you want to spend on CPU work.
Where is this DX9 and JC stuff coming from? I never mentioned DX9 or JC in my original post. Of course, when overhead can be up to 100x more (mixed with other software/hardware advantages), it's not hard to see around a 2x advantage (with similar hardware).There was never any claim that the article wasn't pertaining to DX11. Nor was there any claim that the graphs posted were inaccurate. The argument was and always has been (and I'm not sure how you missed this given how many times it has been repeated) that JC's comment of a 2x console performance advantage at a given performance level was no longer completely relevant due to it being made in respect to DX9, which is considerably less efficient in terms of overhead compared with DX11.
Obviously, most longstanding B3D members understand JC's comment to be a highly simplified statement for the benefit of the less technically minded and that in fact the actual advantage varies greatly from situation to situation depending on workload requirements, system bottlenecks and general levels of optimisation for each platform. But whatever part of his statement related to API overhead is certainly less relevant when using DX11 compared to using DX9 which is the API the statement was made in respect to. And to go further, whatever element of JC's statement was based on the ability to optimise for 1 specific platform / architecture is likely also made less relevant this generation by the fact that the new consoles share a considerable amount in common with the PC in both their CPU and GPU architectures.
I think Windows PCs could use the efficient software in consoles just as much or more than consoles could use the highest end hardware PCs could provide. We know that level of software performance won't/can't happen in the Windows PC environment, though. Developers must target lower GPU set-ups for profits. And, developers can't focus on one particular hardware set.
I agree, however aren't CUDA cores less flexible (switching between physics tasks and graphics)?
I would say the true diminishing returns scenario is in the graphics department and not with the ACEs. That, much like your statement, is just a guess.
Where is this DX9 and JC stuff coming from? I never mentioned DX9 or JC in my original post. Of course, when overhead can be up to 100x more (mixed with other software/hardware advantages), it's not hard to see around a 2x advantage (with similar hardware).
It still seems bad according to the article and Timothy Lottes. I think even Sebbi had something nasty to say about the overhead. That member comparison chart between DX11 and OpenGL looked pretty horrible, too. LibGCM is suppose to be that much better than OpenGL. I'm not talking about the difference between DX9 and DX11 draw call overhead. However, it WOULD be nice to see that data. I just don't think it will show up.
@Lucid_Dreamer and others
You guys really need to get reality check on claims You make
In reality,when it comes to perceived graphics quality, God of War 3, Last of us, Gears of War 3, Uncharted 3 are more or less in the same ballpark as Crysis 3 on highend PC. Maybe it's all about art, not performance but the point still stands.
Draw call overhead on PC is considerably higher compared to consoles. On a console you can just write a few bytes (command header + data) directly to the ring buffer (existing in same unified memory system). That's just a few CPU cycles. You can just ignore all the CPU and GPU synchronization if you know what you are doing (you manage the life time of your data properly, and make sure you are not modifying the data while the GPU is accessing it - for example by manually double buffering the resources)....I think even Sebbi had something nasty to say about the overhead...