I would say with the Tegra 2 and a 4-inch screen, the iPhone 5 would be even more unstoppable than the current iPhone 4, which already works like a dream!
I agree. Those are the two upgrades that I think the phone most desperately needs. Also, since both the Tegra 2 and the Marvell Tri-Core 628 natively output HD content, a mini hdmi port would be pretty cool as well.
There are so many different up and coming mobile SOCs, CPUs and GPUs that it confuses most anyone trying to keep up. For the uninitiated, an SOC is an integrated chip that includes a CPU, a GPU and various task specific processors as well, and each SOC has it's own codename. I thought it would be useful to list all the major ones, how they perform relative to each other, and thus give everyone here a good framework as to what might show up in future iPhones and when.
One key factor when considering mobile CPUs and GPUs is the number of cores, rather than the clockspeed. Mobile CPUs and GPUs must conserve battery life and minimize heat, and mobile devices always downclock their GPUs and CPUs for this reason. Muticore designs go a long way in maximizing battery life and minimizing heat without limiting performance. This is why the CPU I'm most excited about is ARM's 4 core version of the Cortex a15 (coming in 2012) and the GPUs that I'm most excited about are multicore designs such as the 4 core Mali 400.
Another key factor to keep in mind is the actual speed of the ram itself. Mobile ram is extremely slow. While general applications run fine on slow ram, quality graphics benefit greatly from fast ram. The two blazing fast mobile rams available are Mobile XDR (not yet found in any mobile devices to my knowledge, though the PS3's CPU makes use of 256 mbs of XDR ram) and the MoSys 1T-SRAM that is rumored to be found in the Nintendo 3DS and is already found in the Nintendo Wii (24 MBs) and Nintendo Gamecube (24 MBs).
CPUs
ARM Cortex A8 - This is the chip that found itself in all of 2010's most advanced smartphones. It's also found in the iPhone 4 and iPad.
ARM Cortex A9 - This is the chip that's going to dominate 2011. Most of the 2011's most advanced smartphones (including the iPhone 5) will likely feature a dual core version of the Cortex A9. In that configuration, it's more than twice as powerful as the Cortex A8 while consuming less power and generating less heat.
ARM Cortex A15 - This chip should show up in smartphones sometime in 2012. Most configurations will feature a quad core version of the Cortex A15. In terms of performance, it's reported to be five times as powerful as the Cortex A8 found in the iPhone/iPad.
There are obviously other mobile CPUs in the pipeline as well. AMD is working on one. Intel is working on one. And Sony is working on a mobile version of their Cell cpu that may well show up in the PSP2. However, ARM has such a huge headstart over the competitors in the mobile CPU arena that it will likely take years before any of the competitors show up in a smartphone.
GPUs
The most common technique used to benchmark mobile GPU's is the maximum theoretical number of triangles they can render per second. So I included this number where possible. However, that number depends on the clockspeed the GPU is actually being run at. Most SOCs limit the clockspeed of the GPU in order to maximize battery life.
PowerVR SGX535 GPU - 28 million (triangles per second). This is the GPU found in the iPhone 4, iPad and most of Intel's Integrated Graphics Cards found in laptops (GMA 500/600). The iPhone 3GS also uses this GPU but clocked at a mere 200mhz. At that speed, it only pushes 7 million. We don't know what mhz the iPhone 4 and iPad's GPU are clocked at.
nVidia's Custom GPU found in the Tegra 2 SOC - 71 million. This GPU's native support for Unreal Engine 3, OpenGL 2.0, and a dedicated processor for 1080p/HDMI output support are all impressive.
PowerVR SGX540 GPU - 90 million. This is the GPU found in the upcoming OMAP4 SOC, Snapdragon Gen II/III SOC and the Hummingbird SOC. The GPU in the Hummingbird SOC maxes out at 28 million due to it being clocked at 200 mhz and due to limitations related to the memory bandwidth. We will have to wait for the OMAP4 SOC and Snapdragon Gen III to come out before we see if these SOCs have similar limitations.
PowerVR SGX554MP GPU - Unknown performance. This is a GPU that PowerVR announced a week ago with no information at all regarding it's relative performance to other GPU. It's a multicore gpu and thus the performance would scale based on the number of cores used.
Marvell's Custom GPU found in the Tri-Core Armada 628 SOC - Marvell claims that this GPU pushes a whopping 200 million triangles per second. As always, the actual devices will likely limit the clockspeed in order to conserve battery life so the real world performance will be significantly weaker.
ARM Mali 400 GPU - This is the GPU found in the ST Ericsson U8500 SOC and the Samsung Orion SOC. This is a MP GPU that can scale anywhere from 1-4 cores. The only official number ARM released is that the much much weaker ARM Mali 200 GPU pushes 16 million triangles per second. However, Samsung claims that it's Orion SOC featuring this GPU delivers 5x the performance of the Hummingbird. Samsung previously claimed that their Hummingbird SOC is capable of pushing 90 million triangles per second, where as it's real world maximum performance ended up being around 28 million triangles per second. As a result, the rumors regarding the theortical performance of the four core design range anywhere from 130 million to a whopping 450 million triangles per second. However, the key limitation as always is the clockspeed. A four core design could deliver very impressive performance even at a low clockspeed.
For comparison's sake...
Xbox 360's GPU - 500 million triangles per second.
The Playstation 3's GPU - 250 million. This is an unfair characterization. The Cell CPU in the PS3 is actually a graphical beast and can do an astonishing amount of legwork for the GPU when used properly. One reason is that the Cell CPU packs 256 mbs of blazing fast XDR ram that runs a full 4.5x faster than the GDDR3 ram found in the PS3's GPU and Xbox 360's CPU and GPU. XDR ram runs circles around the DDR3 ram used in cutting edge desktops and laptops as well. This is a key reason why the PS3 manages to produce graphics like those found in Uncharted 2/Killzone 2 that nothing on the Xbox 360 comes close to. The ram used in most mobile devices (the Nintendo 3DS being a notable exception) is no where close to running at even GDDR3 speed, much less coming close to the blazing fast speeds of XDR ram. In addition, mobile devices often must downclock their gpu and cpu performance in order to minimize heat and conserve battery life. So don't expect to see PS3 quality graphics until quad core CPUs and GPUs show up in smartphones.
SOCs
iPhone 4/iPad SOC aka. the A4 - Cortex-A8 CPU, PowerVR SGX 535 GPU
Samsung Orion SOC - Cortex-A9 Dual Core 1GHz CPU, ARM Mali 400 GPU
ST Ericsson U8500 SOC - Cortex-A9 Dual Core 1.2GHz, ARM Mali 400 GPU
OMAP4 SOC - Cortex-A9 Dual Core, SGX540 GPU
Qualcomm Snapdragon SOCs - Gen II 1.3GHz Cortex-A8, Adreno 205 - Gen III 1.2GHz Cortex-A8 Dual Core, Adreno 220 GPU aka. PowerVRSGX540 GPU / 1.5GHz Cortex-A9 Dual Core, Adreno 220 aka. PowerVRSGX540 GPU. There was already a Gen I Snapdragon SOC that is now outdated.
Tegra 2 SOC - Cortex-A9 Dual Core, nVidia GPU. nVidia also announced a Tegra 3 planned for the end of 2011 and a Tegra 4 utilizing the ARM Cortex a15 CPU planned for 2012/2013. There was already a Tegra 1 SOC that is now outdated.
Marvell Tri-Core Armada 628 SOC - Three A9 Cores, 1.5 GHz for the two main cores, and 624 MHz for the low power core, all combined with an unknown GPU that Marvell claims will push a whopping 200 million triangles per second.
