Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Apple Confirms: iPad Uses PowerVR SGX Graphics Hardware

Thomas Harte said:
Yep. Tile-based deferred rendering, all the way. And, as of the SGX, now with OpenGL ES 2.0 (ie, fragment and vertex shaders through a high-level language).
Click to expand...

Sadly OpenGL ES is behind in support of geometry tessellation (supposedly the new hotness).

The only downside to TB renderers is how much ram you have to store said tiles (the biggest complaint about the 360 is that it doesn't have enough edram for high resolutions and using more than 1 tile slows graphics down a bunch). I wonder do developers even know how much ram they have access to for video?
 
diamond.g said:
Sadly OpenGL ES is behind in support of geometry tessellation (supposedly the new hotness).

The only downside to TB renderers is how much ram you have to store said tiles (the biggest complaint about the 360 is that it doesn't have enough edram for high resolutions and using more than 1 tile slows graphics down a bunch). I wonder do developers even know how much ram they have access to for video?
Click to expand...

At least on the 3GS, the SGX shares the same memory pool as the CPU and is able to use as little or as much of that as it wants. That's in contrast to the MBX in the 3Gish type devices that can address only 24mb at most.

If the iPad has a shared memory architecture (again, I don't know and I'll wager that those who do can't say while the SDK is under NDA), it's likely the SGX will be able to use all of it in principle.

Vague comments there that don't really answer your question. I'm an iPhone dev but I haven't looked at the iPad SDK yet, so I genuinely don't know whether Apple document memory limits.
 
Thomas Harte said:
At least on the 3GS, the SGX shares the same memory pool as the CPU and is able to use as little or as much of that as it wants. That's in contrast to the MBX in the 3Gish type devices that can address only 24mb at most.

If the iPad has a shared memory architecture (again, I don't know and I'll wager that those who do can't say while the SDK is under NDA), it's likely the SGX will be able to use all of it in principle.

Vague comments there that don't really answer your question. I'm an iPhone dev but I haven't looked at the iPad SDK yet, so I genuinely don't know whether Apple document memory limits.
Click to expand...
Do you know how fast the ram is in the 3GS? I wonder how it compares to the speed of the eDRAM that microsoft uses in the 360.
 
You are not the only one wanting more info on the A4.

DanBUK said:
I'm desperate for some more details on this, the graphics processor and the A4 chip in general- so much still unanswered- just what is the chip capable of?
Click to expand...
I do hope that Apple comes clean soon. Like you I find the A4 to be very interesting and very much worth additional investigation.
Are we talking netbook speeds or better? I know the iPhone OS is fairly light on demands befitting a small battery powered device.
Click to expand...
Actually demand on the GPU goes up with the number of pixels that have to be driven. So by design the iPad needs a more powerful implementation than is in the iPhone. On top of that you are actually spreading a bit of misinformation here, the iPhone actually leverages the GPU in it to a greater extent than the Mac OS when it was delivered. Apple puts that GPU to go use in a very demanding way.

This means that just to maintain the same perception of performance the GPU in the iPad must be significantly more powerful. fortunately this should be a problem as Imagination has muticore models available an process shrinks could easily allow for faster running GPU even if they are of the same generation as the iPhone. Given all of this though I still suspect that there is more going on in A4 than just a nice GPU, thus I expect that there is some sort of hardware decode for the playback of movies.
Which developers will be the first to really produce software that maximises the A4 potential?

It seems to me that this device, like the iPhone will really be a grower.
Click to expand...

Grower? I;m not sure what you mean by that. In any event it is hard to say where this CPU will take Apple. The web is all awash about how fast it is but I've yet to have one in hand, so I'm not sure if this A4 has legs or not.

Dave
 
Interesting comments.

Thomas Harte said:
At least on the 3GS, the SGX shares the same memory pool as the CPU and is able to use as little or as much of that as it wants. That's in contrast to the MBX in the 3Gish type devices that can address only 24mb at most.
Click to expand...
i've skipped the 3GS so don't have experience there. What I'm wondering about is how A4'ish the next iPhone will be.
If the iPad has a shared memory architecture (again, I don't know and I'll wager that those who do can't say while the SDK is under NDA), it's likely the SGX will be able to use all of it in principle.
Click to expand...
I suspect that shared memory is a given but I'm not to sure Apple would give the GPU unfettered access to all of it. That would seem to be a security issue more than anything.

As a side note I've wondered if the A4 has a built in frame buffer or video memory pool. With todays tech there is obviously not enough room for system RAM but a small high speed buffer for use by the GPU could be a big win as the GPU would not have to go off chip to drive the video display. While this might help performance a bit I'm really think more about overall power usage.

With A4 there are so many possibilities that it causes the mind to wonder at length.
Vague comments there that don't really answer your question. I'm an iPhone dev but I haven't looked at the iPad SDK yet, so I genuinely don't know whether Apple document memory limits.
Click to expand...

Apples documents tend to suck with respect to iPhone and the use of the hardware. I think this is on purpose.

Dave
 
Yes it could and most likely does.

sbrhwkp3 said:
Also, if you read the article carefully, it says Apple has confirmed the iPad uses the same family of GPU as the iPhone and iPod touch.

Does this mean that it could be using a much more powerful version of those chips, only with the same architecture?

(Again, I'm new to this, so if that's completely off, don't blast me too bad!) :D
Click to expand...

By default the GPU in iPad would need to be more powerful simply to deliver the performance across all the extra pixels there. There are a number of ways to get that extra performance including a next gen GPU architecture.
 
Are we taking about iPhone 3GS?

ChazUK said:
Wirelessly posted (Mozilla/5.0 (Linux; U; Android 2.1-update1; en-gb; Nexus One Build/ERE27) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17)



Very nice! Is the silicon small enough to engineer into a next Gen iPhone?
As more iPad info is coming its getting better and better.
Click to expand...

I'm not sure what you are after here. IPhone 3GS does have a OpenGL ES 2.0 capable GPU. So in that sense it is already at that level, but don't ask me about part numbers because I don't know.

As to the next gen IPhone I suspect it will get a custom A* chip of some sort. That might be an A4 or more likely an A2. Since this chip would likely represent a process shrink, and further customization by Apple, I suspect that they could significantly increase performance. What the IP for the GPU would be is up in the air, but power (as in watts) can be adjusted to suit the application by adjusting the clock rate and other things.


Dave
 
holmesf said:
Behind? What mobile API supports geometry or hull shaders? And what mobile hardware even supports it?
Click to expand...
OpenGL ES is behind in feature support compared to OpenGL (which is now at 3.2 added geometry shaders and various other things). PowerVR has claimed that the SGX545 supports OpenGL3.2.

Or does OpenGL ES 2.0 support everything the latest version of OpenGL supports now?

Yes no mobile hardware has hardware tesselation (yet) and I would wager that PowerVR would get there first, but when your API doesn't expose all the cool things like that it doesn't matter much does it?
 
diamond.g said:
Or does OpenGL ES 2.0 support everything the latest version of OpenGL supports now?

Yes no mobile hardware has hardware tesselation (yet) and I would wager that PowerVR would get there first, but when your API doesn't expose all the cool things like that it doesn't matter much does it?
Click to expand...

The core spec doesn't, having not been updated since 2004. GL ES 2.0 isn't backwards compatible with 1.0, so I think they're planning on waiting lengthy periods and making huge leaps even more than has proved to be the case on the desktop. However, there is nothing to stop extensions like EXT_geometry_shader4 being exposed.

Wiki does claim that the SGX has hardware tesselation, I don't know how reliable that is.

EDIT: that all said, I maintain that people have done nothing like push the existing hardware. The obvious example is that the MBX on the original phone has the dot3 texturing extension, so can support bump maps. But it doesn't support cube maps, so every "how to bump map with the dot3 extension" tutorial I've seen sitting on the web since 2001-or-whenever doesn't directly translate, and once you've set yourself up with a sphere map for normalisation you've run out of texture units, so it's multipass or no surface texture. So it's something you actually need to think about where best to use rather than an obvious win.
 
DanBUK said:
I'm desperate for some more details on this, the graphics processor and the A4 chip in general- so much still unanswered- just what is the chip capable of? Are we talking netbook speeds or better? I know the iPhone OS is fairly light on demands befitting a small battery powered device. Which developers will be the first to really produce software that maximises the A4 potential?

It seems to me that this device, like the iPhone will really be a grower.
Click to expand...

I would like to know more about the A4 also, as would many. I think we will be surprised at the level of detail Apple included in the chip that is tablet centric.
 
diamond.g said:
Sadly OpenGL ES is behind in support of geometry tessellation (supposedly the new hotness).

The only downside to TB renderers is how much ram you have to store said tiles (the biggest complaint about the 360 is that it doesn't have enough edram for high resolutions and using more than 1 tile slows graphics down a bunch). I wonder do developers even know how much ram they have access to for video?
Click to expand...

You do realize that tessellation support is merely adding more polygons to the model?
 
by the way, iphone 3G has 128mb of ram, 3GS has 256mb. how much ram for the ipad? i hope it's not the same with 3GS. 512mb or 1gb should be plenty..
 
What about the resolution? Won't it need a little bit more power to display iPhone games at a higher resolution?
 
If (when in playing a game mode) the iPad has access to main memory to "Create the Game"

Then, what happens when you are using a lot/most of your 16GB to store Music, Video/Books ?

Will a game no run, or run bad as it's not got enough memory to run in?

I don't even know if the GPU has it's own dedicated memory 256MB, 512MB etc to play with to hold textures? I'm assuming it does, as I also assume "normal" memory is very slow compared to dedicated graphics memory.
 
Piggie said:
If (when in playing a game mode) the iPad has access to main memory to "Create the Game"

Then, what happens when you are using a lot/most of your 16GB to store Music, Video/Books ?

Will a game no run, or run bad as it's not got enough memory to run in?

I don't even know if the GPU has it's own dedicated memory 256MB, 512MB etc to play with to hold textures? I'm assuming it does, as I also assume "normal" memory is very slow compared to dedicated graphics memory.
Click to expand...


Are you confusing the 16GB disk space with the RAM?
 
padgamer said:
I'm pumped about this OnLive technology, which supposedly is going to allow us to play high-end games on any device, like the iPhone or iPad. Hopefully this chip will enhance performance of OnLive.

http://www.ontheipad.com/component/content/article/41-ipad-apps/98-crysis-coming-to-ipad-games
Click to expand...
The only thing that OnLive cares about is the speed of your internet connection. The servers on the back end do all the video processing. So having an iPad would just give you a bigger screen (and not much else).

Piggie said:
If (when in playing a game mode) the iPad has access to main memory to "Create the Game"

Then, what happens when you are using a lot/most of your 16GB to store Music, Video/Books ?

Will a game no run, or run bad as it's not got enough memory to run in?

I don't even know if the GPU has it's own dedicated memory 256MB, 512MB etc to play with to hold textures? I'm assuming it does, as I also assume "normal" memory is very slow compared to dedicated graphics memory.
Click to expand...
Based on what was said earlier there is no dedicated ram for the GPU. All the RAM in the system is shared (which can cause huge bandwidth problems for really complex stuff). Do games have access to the storage to write textures (is anyone even doing real time procedural textures) to? I am thinking of things like what .theprodukkt did in .kkrieger.
 
So does this mean it's likely that the next iPhone will have the 1Ghz A4 chip in it, or something very similar in it to compete with the Nexus hardware?
 
Becordial said:
So does this mean it's likely that the next iPhone will have the 1Ghz A4 chip in it, or something very similar in it to compete with the Nexus hardware?
Click to expand...

Depends on the power requirements. It seems like the biggest power hog in the iPhone is the cell radio so if the A4 has the same power footprint as the A8 they are using now then sure they will probably go with their own part. The next phone has to have equal to or better than 5 hours talk time (over 3g).
 
iPad = A4, iPhone 4g = A2?

Anyone wondered what A4 means? What happened to A1, 2 and 3?

My guess: It's Apple 4-core. Quad core for the ipad, dual core (A2) for the next iphone. I suspect that because it's likely using the cortex A9 CPU, which is designed to come in either dual or quad core configurations. Dual for the iphone is likely, so quad for the ipad makes some sense.

The GPU will be either the SGX 540 or 545 I guess.. the 3GS has a 535, I'd expect it to be more powerful based on the huge increase in screen size. Imagination also do a bunch of 'higher end' parts (the 5XT series I think it's called) that could be a better fit. We'll have to wait and see though.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back