4 years later, iPhone graphics still worse than PSP

[edepot]

Can it be possible? The most powerful iPhone 3GS (released around 4 years AFTER the PSP) still has worse 3D graphic capabilities than the PSP. How is this possible? Or am I mistaken?

Here are some iPhone secrets:

http://www.edepot.com/iphone.html

Trying to get it accurate, so constructive criticism (not flames) appreciated.

 

[Grall]

Define "worse" please... The PowerVR design in the 3GS is vastly more powerful from a capabilities standpoint (it supports pixel shading, antialiasing, overdraw elimination in hardware and so on). It should also be considerably more powerful from a purely technical point of view.

Then you got to remember the 3GS is not primarily a gaming machine. Many games will be poorly optimized, and aimed at customers that do not care that the framerate is jerky. The iPhone CPU also has to run other tasks than a game, stuff that's way higher priority.

There's no proper gaming input mecanism with tactile feedback on the iPhone, so controls will be fiddlier and sloppier, further pushing the purist gamer away in favor of the more casual.

So I don't think a technical comparison between the two devices can be made like that without taking a full look at the big picture. The PSP is a games machine and the iPhone is not. Therefore, games will look better on the PSP, even though in comparison its hardware is rather dated. People did amazing things with crappy hardware, such as FLI on the ol' C64 breadbox, and even though nobody will ever push the PSP to such an extent, it's still a far more focused, dedicated gaming device.

 

[Brad Grenz]

I think it's mostly a production quality problem. No one is investing the time or money to create $40, PSP scale games for the iPhone. So the art quality isn't there and the engine optimization isn't there.

 

[Arwin]

I think it's mostly a production quality problem. No one is investing the time or money to create $40, PSP scale games for the iPhone. So the art quality isn't there and the engine optimization isn't there.

Don't you lose a lot of performance versus the PSP basically because on the PSP you can code to the metal, and on the iPhone you use an abstraction layer? Of course the PSP also has EDRAM, which may give it an edge in some areas, even today, and codes have been building up experience for a while now as well as have been able to reuse a lot of their PS2 prowess.

Also, in the end power use remains an important bottleneck for all portable electronic devices. There's no denying though I think that the PSP holds its own very well for a device that I bought in (late) 2004.

 

[Nick]

Can it be possible?

The day you can use your PSP to call your mom, surf the internet anywhere using an on-screen keyboard and fit it in the pocket of your tightest jeans, people might actually start to care.

 

[Grall]

Of course the PSP also has EDRAM, which may give it an edge in some areas

The iPhone uses a SoC design with all major computing components on one silicon die; CPU, GPU, RAM (and flash too from what I recall). So it essentially has eDRAM as well you might say.

Besides, the PowerVR GPU is far less needy of high bandwidth thanks to its hidden surface removal tech, than a straight-up brute-force rasterizer like in the PSP.

 

[tongue_of_colicab]

Can it be possible? The most powerful iPhone 3GS (released around 4 years AFTER the PSP) still has worse 3D graphic capabilities than the PSP. How is this possible? Or am I mistaken?

Here are some iPhone secrets:

http://www.edepot.com/iphone.html

Trying to get it accurate, so constructive criticism (not flames) appreciated.

Well... Maybe one being a phone and the other being a handheld gaming device has something to do with it?

 

[Arwin]

The iPhone uses a SoC design with all major computing components on one silicon die; CPU, GPU, RAM (and flash too from what I recall). So it essentially has eDRAM as well you might say.

On the other hand, doesn't that mean it probably doesn't have any dedicated graphics memory, just general 256MB of RAM that's shared between the GPU and the CPU? And what's the bandwidth of that RAM? If that's universal 256MB RAM, it's probably not going to be crazy fast? The PSP's EDRAM is 4MB of dedicated video memory and combined with the two VMX capable media processors it can do some pretty nifty stuff. The big advantage of the iPhone is obviously that there is more memory available, but it's speed may still be limiting

Besides, the PowerVR GPU is far less needy of high bandwidth thanks to its hidden surface removal tech, than a straight-up brute-force rasterizer like in the PSP.

Well, I'm way out of my league here anyway in terms of being able to discuss the iPhone's hardware. But for now, the PSP has a clear advantage still. We'll have to wait and see if we get 3GS optimised applications at some point that can show what it can really do. Being compatible with 3G is going to hold back iPhone applications for a fair while I think, if you look for instance at the huge differences between Assassin's Creed 2 on PSP and iPhone. There too, we see a big advantage for the PSP in that so many 3D engines have been developed for it already (the three Prince of Persia games for instance), and it would have been interesting to see how much they could have done on the iPhone had they designed it for the 3GS. Who knows at some point we'll see applications ported from the PSP to the 3GS, or vice versa - perhaps OpenGL ES 2.0 support on the iPhone helps there.

 

[Ailuros]

Well... Maybe one being a phone and the other being a handheld gaming device has something to do with it?

It's the lack of content that doesn't differentiate it yet from handhelds and not the hardware. The hardware is across the board more capable than that of a PSP and not just by a magnitude of 2x.

Would you surprised if you could make eventually calls also from Sony's next generation handheld and would it be held back also in performance despite having the same graphics technology under the hood as the iPhone?

On the other hand, doesn't that mean it probably doesn't have any dedicated graphics memory, just general 256MB of RAM that's shared between the GPU and the CPU? And what's the bandwidth of that RAM? If that's universal 256MB RAM, it's probably not going to be crazy fast? The PSP's EDRAM is 4MB of dedicated video memory and combined with the two VMX capable media processors it can do some pretty nifty stuff. The big advantage of the iPhone is obviously that there is more memory available, but it's speed may still be limiting

I doubt for the moment either/or would do any that advanced stuff that any siginficant differences could be visible. But if it would come down to any advanced stuff like MRTs you'd be surprised to hear that a TBDR under conditions doesn't have to use external memory.

Well, I'm way out of my league here anyway in terms of being able to discuss the iPhone's hardware. But for now, the PSP has a clear advantage still. We'll have to wait and see if we get 3GS optimised applications at some point that can show what it can really do. Being compatible with 3G is going to hold back iPhone applications for a fair while I think.

Who says that PSP has any hw advantage even against the iPhone3G?

 

[tongue_of_colicab]

Better hardware or not is irrelevant as people who buy a iPhone by a iPhone because they want a phone (with internet etc), not because they want a handheld gaming system so why should anyone bother spending time and money making a really good looking game when 99,999% of the people who own a iPhone wont care? Its the opposite for the psp. People buy that because they want to play games on it so they expect the hardware to be put to good use.

 

[Grall]

On the other hand, doesn't that mean it probably doesn't have any dedicated graphics memory, just general 256MB of RAM

I'm not sure how much RAM the iPhone 3G(S) has, but you're most likely right it has no dedicated VRAM. Then again, it doesn't really need it, since as already mentioned, its GPU is a tile-based deferred renderer, so its bandwidth requirements are quite low, and the iPhone's screen resolution is very low also. A full-screen framebuffer is tiny, so there's no need to be concerned here.

The PSP's EDRAM is 4MB of dedicated video memory and combined with the two VMX capable media processors it can do some pretty nifty stuff.

Only those 4MB are on-die with the PSP, the main RAM is off-chip. And that's...what? 16MB? 32? As for the two media processors you mentioned, AFAIK I know of only one media processor (the other's the vector maths co-processor to the CPU), and at least early on in the PSP's lifespan that media processor was not opened up to the developer.

Anyway, iPhone has a 600MHz CPU that's generations more recent than what's in the PSP, along with advanced floating-point vector extensions and other modern stuff. It's just way faster really.

Like I said, the only real reason the PSP's games look better than the crap available for the iPhone is the target audience. Nobody's actually even TRYING to do high-end stuff on the iPhone; there's no market for it, you would just lose money.

Other than when it comes to interaction with the device itself (buttons, joystick etc), iPhone has the clear advantage from a hardware point of view. A touchscreen simply can't beat a proper D-pad, shoulder triggers and front face buttons other than for certain casual gesture-based games.

A proper PSP 2 (instead of that half-baked PSP Go) with proper buttons and iPhone-like hardware innards would just blow the old PSP out of the water. It wouldn't budge the iPhone crowd though, since they want an iPhone, not a games machine.

 

[Arwin]

I'm not sure how much RAM the iPhone 3G(S) has, but you're most likely right it has no dedicated VRAM. Then again, it doesn't really need it, since as already mentioned, its GPU is a tile-based deferred renderer, so its bandwidth requirements are quite low, and the iPhone's screen resolution is very low also. A full-screen framebuffer is tiny, so there's no need to be concerned here.

Only those 4MB are on-die with the PSP, the main RAM is off-chip. And that's...what? 16MB? 32? As for the two media processors you mentioned, AFAIK I know of only one media processor (the other's the vector maths co-processor to the CPU), and at least early on in the PSP's lifespan that media processor was not opened up to the developer.

32MB main RAM on the 1k, 64MB on later models (but in games that can only really be used for caching UMD reads and reduce load-times I think, to maintain compatibility with the older models).

You can call it vector maths co-processor, but afaik they are the exact same chips (what was it, MIPS 4k?). I don't know if it was or wasn't opened up, but it's open now anyway. They also are allowed to run at up to 333Mhz now, instead of 222Mhz at launch. So two of these processors at 333Mhz, may be more capable than you'd think.

Anyway, iPhone has a 600MHz CPU that's generations more recent than what's in the PSP, along with advanced floating-point vector extensions and other modern stuff. It's just way faster really.

But you can't program it directly, can you? Which typically means a pretty big limitation on performance, added to all the other question marks. And like you say, with framebuffers being small (both have 480x272 resolution or something similar) that 4MB is quite sufficient. It's not just for drawing those triangles either - with direct framebuffer access you can do a lot of cool little things, like for instance the fog effects in the Tekken 5R swamp levels that Namco had trouble replicating even on the PS3 for the PSN release of Tekken 5.

Combine that with the PSP's 3D graphics probably being more than powerful enough for the small screen, and you get the near PS2 quality graphics that we see today in many cases.

Like I said, the only real reason the PSP's games look better than the crap available for the iPhone is the target audience. Nobody's actually even TRYING to do high-end stuff on the iPhone; there's no market for it, you would just lose money.

May be true, but in practice I think that the original iPhone falls between the DS and PSP. The 3GS should be able to match the PSP, but I'm not even sure if that would hold for all scenarios, and while I'm sure the hardware in the 3GS would shine in a device like the PSP, in the iPhone I'm not so sure. Maybe someone else who's got experience can share with us how much is lost, if any, due to programming limitations imposed by having to run on the iPhone's OS?

A proper PSP 2 (instead of that half-baked PSP Go) with proper buttons and iPhone-like hardware innards would just blow the old PSP out of the water. It wouldn't budge the iPhone crowd though, since they want an iPhone, not a games machine.

Well I agree here on all counts.

 

[silent_guy]

May be true, but in practice I think that the original iPhone falls between the DS and PSP. The 3GS should be able to match the PSP, but I'm not even sure if that would hold for all scenarios, and while I'm sure the hardware in the 3GS would shine in a device like the PSP, in the iPhone I'm not so sure.

Why would the hardware of a 3GS shine in a PSP but not in the iPhone?

MBX-lite is pretty limited GPU core, but the SGX is a full featured OpenGL ES 2.0. Other than reading from your render target from within a shader (which is not supported by OpenGL), it should beat the PSP at everything.

There's no doubt in my mind that this is really a matter of SW guys not trying very hard. (And who could blame them? App prices are too low and they still need to support older iPhones anyway...)

 

[Panajev2001a]

Why would the hardware of a 3GS shine in a PSP but not in the iPhone?

MBX-lite is pretty limited GPU core, but the SGX is a full featured OpenGL ES 2.0. Other than reading from your render target from within a shader (which is not supported by OpenGL), it should beat the PSP at everything.

There's no doubt in my mind that this is really a matter of SW guys not trying very hard. (And who could blame them? App prices are too low and they still need to support older iPhones anyway...)

I think that the OS/driver layer is much heavier on iPhone/iPod Touch than on PSP, also on PSP you have a full blown CPU and co-processors dedicated to OS tasks, audio, and video (Media Engine: 333 MHz R4000i with FPU + AVC decoding chip + VME configurable sound DSP) which help the main CPU and GPU not feel the OS/system tax.

AFAIK, developing on iPhone is more like developing on a PC than a console.

 

[Panajev2001a]

I'm not sure how much RAM the iPhone 3G(S) has, but you're most likely right it has no dedicated VRAM. Then again, it doesn't really need it, since as already mentioned, its GPU is a tile-based deferred renderer, so its bandwidth requirements are quite low, and the iPhone's screen resolution is very low also. A full-screen framebuffer is tiny, so there's no need to be concerned here.


Only those 4MB are on-die with the PSP, the main RAM is off-chip. And that's...what? 16MB? 32? As for the two media processors you mentioned, AFAIK I know of only one media processor (the other's the vector maths co-processor to the CPU), and at least early on in the PSP's lifespan that media processor was not opened up to the developer.

PSP has 32 MB of main RAM, 64 MB from the PSP-2000 revision forward.
Also, the point of the Media Engine (same R4000i core as Allegrex minus the VFPU, but including a standard FPU + AVC decoder + VME configurable sound DSP) is to offload OS tasks and other I/O+media tasks to it and let your game code run as quickly as possible. What the Media Engine on PSP (with its 2 MB of dedicated e-DRAM) and the reserved SPU on PS3 help you to obtain is more deterministic performance for your game applications.

iPhone is not thought as a real game platform, but more as a portable multi-purpose device and efficiency suffers.

Anyway, iPhone has a 600MHz CPU that's generations more recent than what's in the PSP, along with advanced floating-point vector extensions and other modern stuff. It's just way faster really.

I recall Allegrex's VFPU (Allegrex is PSP's main CPU) being really appreciated by more than one developer . I do not know how NEON/VFP compare to it

 

[edepot]

Real 3D benchmarks of iPhone 3GS

Here is the manufacturer's specs (theoretical, and not real world)...

PowerVR SGX 535 (iPhone 3GS): 28 M triangles/s, 400 M pixels/s
Sony PSP: 33 M triangles/s, 664 M pixels/s

Here is the "real world" benchmark...

http://www.glbenchmark.com/phonedetails.jsp?benchmark=glpro11&D=Apple iPhone 3G S&testgroup=lowlevel


The iPhone 3GS can only do 6.538 million triangles per second under OpenGL 1.1 (2.0 should be similar) using the most basic flat shaded color.

http://www.glbenchmark.com/phonedetails.jsp?benchmark=glpro11&D=Apple iPhone 3G&testgroup=lowlevel

The iPhone 3G can only do 670 thousand triangles per second under OpenGL 1.1 (2.0 should be similar) using the most basic flat shaded color.

So the iPhone 3GS can do 10 times more triangles than iPhone 3G.


The PSP can do 33 million theoretical triangles per second (again the most basic flat shaded color). I could not find real world figures, but I think some mentioned 60% of that is realistic.

So the PSP can do almost 3 times more triangles (in the real world) than the iPhone 3GS. I think the GPU is stuck at 150Mhz on the iPhone 3G or 3Gs which is why the figures are so low.




Some old PSP facts (needs updating with great info above)
http://www.edepot.com/reviews_sony_psp.html

 

[Ailuros]

If theoretical triangle rates and/or GFLOPs would be an accurate measurement to define a GPUs performance it would be a lot easier to evaluate any of them based on raw paper specs.

The GL benchmark you've searched for has some inevitable restrictions (vsync, CPU bound etc.) that doesn't allow the 3GS to stretch its legs. As long as you don't have any comparable results from a PSP in that particular benchmark any assumption that supposed real time throughput is by that and that much higher or lower is completely useless.

And who cares anyway? A handheld is a handheld and iPhone3G and 3GS are smartphones in essence, else two completely different animals.

If SONY isn't able to evaluate a chips capability accurately, they'd be quite dumb to have licensed SGX IP for their next generation handheld and yes you can quote me on that one whenever it gets announced in the less foreseeable future.

 

[sethk]

I would say developing on the iPhone is halfway between developing on the PC and a console. It's a semi-fixed spec, there isn't an endless variation of RAM, CPU speeds and capabilites. But it's not completely fixed - there are a couple of variations.
As to the SDKs and low level access, the situation is complicated. The current public APIs expose a lot more than say something like the Palm Pre (hacking aside), and the private APIs are very well documented and explored by the unofficial programming community. I am not sure how much App Store apps can get away with in terms of using the private APIs (writing and compiling the code is not a problem) if the end result is not blatantly going outside what the API allows in terms of communications, etc. Since this is compiled code, I don't know how closely Apple scrutinizes the end results. I've seen stories about some App Store app submissions that implemented features not possible with the public APIs, so I think clearly this must be a common practice at this time. And game developers are usually not shy about pushing boundaries. Accessing very low level instruction sets and bypassing OpenGL etc. are probably still not common in games, I would think.

Overall, I think if a talented development house spent the kind of budget that devs have on say God of War: Chains of Olympus or MGS: Peace Walker on a dedicated 3GS game, you could probably eclipse what the PSP is capable of.

 

[Lazy8s]

The PSP's GPU was more than 500% the size of the original iPhone's at the same process node, so belonging to a completely different class of device is just another point of incomparability along with differing levels of abstraction of the hardware, focus of the drivers, and overhead from the OS.

 

[Blazkowicz]

I remember seeing the iPhone and thought it had very bad texture filtering, but I'm spoiled by the PC.
This is unrelated to software libraries, abstraction and all. But it is probably one way they save trannies.
I've played a bit of original Playstation and was quite shocked. The GPU has almost no feature whatsoever