NVIDIA Tegra Architecture

Battlefield 3 does support DX10 GPUs. I thought therefore DirectCompute was optional rather than falling back to Compute Shader 4.x?
Sorry, I meant DX11 API rather than DX11 GPU. I can't see how they'd port their tile-based deferred shading algorithm to a system without DirectCompute/shared memory, so they'd have to revert to traditional deferred algorithms which would be very bad for performance unless they reduce the number of lights (which might have gameplay implications) - I'd tend to believe it's more likely they're using CS4.x but I'm not sure. I'd love to know more details about which DX11 API-only features they're using.

I believe compute shaders were integrated in OpenGL 4.3 not 4.2.
Oops, correct :) It's easy to lose track of how long it took for OpenGL to get on the same level as DX11! ;) It's a pretty good API nowadays though obviously.

Besides graphical/performance limitations and the naturally shorter gameplay sessions of mobile the other issue is going t obe development budget impeding development of very immersive mobile games. I don't think even big developers are generally willing to risk the 10s or 100s of millions of dollars and "when it's done" indefinite development time that console/PC games can get on a mobile game. Admittedly big budget doesn't necessarily translate into a fun, immersive game, but mobile games are certainly not on an even playing field in this regard.
Agreed. I suppose the main short/mid-term approach will be porting existing AAA games but even that is very difficult due to the lower performance and especially touchscreen controls.

I can't remember which developer mentioned this (might have been repi from DICE on Twitter actually), but I agree that the next big thing on handhelds has got to be high precision eye tracking. If you can actually get it to work reliably (high resolution image to analyse and proper compensation for the eye naturally scanning around all the time etc.) then that's a completely new control scheme which could be an order of magnitude better than touchscreen for games (while still allowing touchscreen controls at the same time where it makes sense). But then there's also a question of where best to process that data; ideally handheld GPGPU should be mature enough by that point to do it on the GPU but we'll see :)

But now I'm getting even more off-topic so I'll just stop here. Then again this isn't really that off-topic in a sense; while I was talking about SGX, the exact same points apply for Tegra 4: the lack of ES3 compliance isn't a deal breaker and the increase in performance remains the most important element for this generation of hardware. If you give me a choice between ES3 and framebuffer compression on a bandwidth starved IMR, I'll always choose the framebuffer compression.
 
Sorry, I meant DX11 API rather than DX11 GPU. I can't see how they'd port their tile-based deferred shading algorithm to a system without DirectCompute/shared memory, so they'd have to revert to traditional deferred algorithms which would be very bad for performance unless they reduce the number of lights (which might have gameplay implications) - I'd tend to believe it's more likely they're using CS4.x but I'm not sure. I'd love to know more details about which DX11 API-only features they're using.
http://publications.dice.se/attachments/GDC11_DX11inBF3_Public.pdf

I'm not very knowledgeable in this area but I was basing this on slide 11 of the above presentation where they said that their tile-based deferred shading technique requires Compute Shader 5.0 for their lighting.

http://publications.dice.se/attachments/BF3_NFS_WhiteBarreBrisebois_Siggraph2011.pdf

For DX10 GPUs, they may be doing something similar to their tile-based deferred shading approach on the XBox 360 which of course doesn't support compute shaders or SPUs. (Page 64).

EDIT:
http://dice.se/jobs/mac-os-x-engineer/

Coincidentally, DICE is now hiring engineers to port Frostbite to OS X which only supports up to OpenGL 3.2 and no compute shaders. If they aren't going to be using OpenCL on Mac and are able to implement their tile-based deferred shading in OpenGL 3.2, then presumably getting Frostbite up on OpenGL ES 3.0 would be less about features than performance.
 
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P.S.: On a separate note, please let me know when any handheld game is anywhere as awesome as TW2. Except for some adventure game ports, I haven't seen any good story-based game, and nothing as immersive (possibly because handheld games are more optimised towards shorter gameplay sessions).

Well.. there's all the over-priced JRPG ports of the 16-bit and 32bit eras from Square-Enix...



As for going on-topic, I think the lack of any OpenCL will come as a lot more of a deal breaker than the lack of ES 3.0 in Tegra 4.
 
John, I think french toast needs a real-world example where the limitation is clearly performance rather than features. Here's the most perfect example I can think of: The Witcher 2. It's still fully a DX9 game (which looks better than many DX10 and even DX11 games). SGX544/SGX554 are fully DX9 compliant.

Therefore, the only limitation for SGX544 to run The Witcher 2 at maximum quality settings is performance and nothing else. Now tell me honestly that this doesn't look many generations ahead of anything you've ever seen on a handheld:

http://assets1.ignimgs.com/2012/03/...nhanced-edition-20120308095456731-3611513.jpg
http://www.geforce.com/Active/en_US...s/TheWitcher2AssassinsOfKings-05042011-06.jpg
http://www.geforce.com/Active/en_US...s/TheWitcher2AssassinsOfKings-05042011-03.jpg
http://www.geforce.com/Active/en_US...s/TheWitcher2AssassinsOfKings-05042011-08.jpg

As I said, there's nothing that prevents SGX544 from running this except performance. Now that's not quite true for OpenGL ES2.0 in general; you do need MRT support for deferred rendering among many other things, but SGX will support all of these features and Khronos is widely expected to standardise a significant number of OpenGL ES3.0 features into standard extensions that multiple vendors will support.

Yes, there are features in DX10/DX11 (some of which are in ES3; many of which are not) which would allow The Witcher 2 to run faster/more efficiently on the same hardware. But they also cost area/power to implement so the increase in perf/watt might not be as large as you'd expect it to be. And I would describe ES3 as a very evolutionary API, its main advantage is that it standardises many extensions that have existed on some hardware for many years.

If you look at Battlefield 3, it makes very good use of tesselation, but there's only one real reason why it's a DX11-only game: DirectCompute shaders which they use for their excellent deferred rendering implementation. OpenGL 4.2 now includes compute shaders inside the API rather than requiring the developer to use OpenCL (and all the problems that can cause) but unfortunately that's not the case in OGL ES3.0 yet. Personally I completely agree with the idea that graphics is the killer app for compute, but unfortunately handhelds are not ready for it either in terms of API support or architecture (too many incompatible optimisations for different architectures e.g. shared/local memory bank conflicts). That's a much bigger problem than ES2 vs ES3 support in my opinion.

P.S.: On a separate note, please let me know when any handheld game is anywhere as awesome as TW2. Except for some adventure game ports, I haven't seen any good story-based game, and nothing as immersive (possibly because handheld games are more optimised towards shorter gameplay sessions).

Thanks arun that explains it very well, obviously the witcher2 is a very complex full pc game...so we wouldn't expect such graphics to be rjn on mobile hardware. ..what im talking about is more basic mobile games perhaps running epics unreal engine 3..and using more effects than are being used now...utilised by in game settings according to your hardware. .similar to pcs...

I know performance is far to lacking to be running dx11 level features on mobile at hd...but we could be doing alot better...we will see more graphically intense games over the next year running quite nicely on current hardware..guarenteed :)


Had a read up on halti features over standard gl es 2.0....multiple render targets, occlusion queries to help with geometry and stress on cpu, full precision (32bit) integer and floating point shaders..which in my limited understanding should enable more complex effects..
high quality ETC2 / EAC texture compression...again I think thst means higher quality textures being made available at less bandwidth cost.. transform feedback.. (lighting?)
And of course open cl..which I assume would be good for a lot of things including physics and AI.

Some of those or maybe most of those perhaps are available on extentions to d3d 9.3 level hardware such as sgx 544/554 adreno 225?..

Despite that Im sure those features are not being put into practice right now..and im guessing on hardware pointed out above those features could be implemented on games already produced. .as currentd games run very nicely on adreno 205/220 sgx 540/543 type hardware...im just saying there is a window to make better games....I only didnt realise at the time (thanks to john) that most of the features I only expected to see in halti are in fact available now via extensions in gpus outlined above.
 
Oh dear. .dead on arrival.

Not really; besides the unfortunate delay due to the respin necessity, it has been always clear to me that smartphone design wins for NV could not come to a real kickstart before Grey is available for mainstream smartphone deals.
 
Not really; besides the unfortunate delay due to the respin necessity, it has been always clear to me that smartphone design wins for NV could not come to a real kickstart before Grey is available for mainstream smartphone deals.

Necessity or not...they planned (and needed) tegra 4 as early as possible....snapdragon 800/600 will be well underway by then....with only the now pretty lame tegra3 to hold the fort across smartphones and tablets till september time....nvidia is actually going to be going backwards this year after qualcomms domination last.

Not good for an nvidia invester.
 
The problem is actually way deeper. While the desktop GPU market roadmaps are slowing down due to manufacturing process milestones, NV isn't growing fast enough with Tegra. If processes shouldn't also slow down SFF mobile development I'm afraid there might be a gap between the two markets evolving at different paces and obviously NVIDIA needs to grow with Tegra.

Obviously the delay of T4 is not for NV's benefit since they inevitably have lost some design wins (the Nexus7 successor for instance according to rumors), but it's not a disaster yet either. The critical point is if Grey will show up as NV has projected and if it'll stand up to their expectations. NV needs volume and decent volumes you can only find in mainstream and lower markets.

When a statistic states for instance that Samsung sold for the last year over 230M smartphones, guess where the highest volume actually lies. I doubt anyone thinks that the majority of that vast sales volume consists to its majority from GalaxyS3 sales. Only other exception would be Apple, where it's for the moment just iPhone and therefore high end smartphones only.
 
The problem is actually way deeper. While the desktop GPU market roadmaps are slowing down due to manufacturing process milestones, NV isn't growing fast enough with Tegra. If processes shouldn't also slow down SFF mobile development I'm afraid there might be a gap between the two markets evolving at different paces and obviously NVIDIA needs to grow with Tegra.

Obviously the delay of T4 is not for NV's benefit since they inevitably have lost some design wins (the Nexus7 successor for instance according to rumors), but it's not a disaster yet either. The critical point is if Grey will show up as NV has projected and if it'll stand up to their expectations. NV needs volume and decent volumes you can only find in mainstream and lower markets.

When a statistic states for instance that Samsung sold for the last year over 230M smartphones, guess where the highest volume actually lies. I doubt anyone thinks that the majority of that vast sales volume consists to its majority from GalaxyS3 sales. Only other exception would be Apple, where it's for the moment just iPhone and therefore high end smartphones only.

Yes we await for grey.... its not an ideal situation for nvidia....as for mainstream pc gpus..I think the next big innovation is actually going to be low latency sram implementation. ...similar to what we are going to see with 720..and to a lesser extent 360?....as graphics move more towards dx11 and gpgpu compute for ingame effects etc...it will start to make some sense.

(Based on discussions we are having in durango thread s)
 
Sadly Shield will not come out until May 2013 at the earliest. Hopefully there will be reviews and pre-ordering in advance though.
 
Now I see why Nvidia didn't go for unified shaders in T4/Wayne, so they can reuse the same GPU architecture on the T4i/Grey.

Hope the next time they will go with unified shaders for Logan and Grey's successor.
 
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