A closer look at iPhone 3G S Cortex-A8 ARM and PowerVR chips
The iPhone 3G S uses a Samsung processor incorporating an ARM Cortex-A8 processor core and Imagination's PowerVR SGX graphics core to achieve a significant new class of speed while remaining backwardly compatible with existing iPhone apps.
The use of the Cortex-A8 core has been cited by multiple sources, including an analysis by AnandTech. This makes the new iPhone 3G S very similar in terms of processor design to the Palm Pre, although Palm's phone uses a device built by Texas Instruments.
ARM Processors
The Cortex-A8 is a seventh generation CPU core design licensed by ARM to a variety of manufacturers. The vast majority of all smartphones, handheld games and other mobile devices use ARM processors.
The Cortex-A8 class is referred to in general terms as ARMv7, not to be confused with ARM7, which was actually a third generation ARMv3 used in the Apple eMate300 a decade ago. Previous generations of iPhone and iPod touch used an ARM11 processor, part of the ARMv6 generation.
Apple partnered with its British equivalent Acorn in the late 80s to adapt Acorn's RISC processor for use in mobile devices, forming the ARM partnership. Apple subsequently used a third generation ARM6 in its first Newton MessagePad in the early 90s.
By the time the company discontinued its Newton and eMate devices in 1998, ARM processors had become the most popular mobile processors available, in part due to ARM's licensing of its highly efficient technology to a variety of chip manufacturers. Steve Jobs sold batches of Apple's shares in the ARM partnership at a huge profit to help keep the company afloat.
When the company introduced the iPod in 2001, it used a fourth generation ARM7TDMI processor. The latest generations of the AirPort Extreme also use an embedded ARM processor.
S is for speed
The Cortex-A8 in the iPhone 3G S sports "a two-issue in-order core, capable of fetching, decoding and executing two RISC instructions in parallel," according to AnandTech's report, which also notes, "the ARM11 processor in the iPhone/iPhone 3G has a basic vector floating point unit, but the A8 adds a much more advanced SIMD engine called NEON. The A8 also has twice as many double precision FP registers as the ARM11."
"The combination of higher clock speeds, more cache and a dual-issue front end results in a much faster processor," the report states. "Apple claims the real world performance of the iPhone 3GS can be up to 2x faster than the iPhone 3G, and I believe that?s quite feasible."
The report states that if the processor is running at 600MHz, it would draw three times the power of existing iPhone processors, but notes that in typical use, the device spends a lot of time in standby. Separately, Apple has detailed technologies for maximizing the performance of a processor by running it at less than its top rated clock speed while scheduling tasks more efficiently. This was done with the original iPhone.
As a result of new efficiency measures, Apple claims significantly longer battery life over the current iPhone 3G when using the iPhone 3G S for general processing tasks despite the big leap in performance and the extra power consumed.
Apple has increased the maximum rated battery life of the iPhone 3G S in WiFi internet browsing from 6 hours to 9 hours, video playback from 7 to 8 hours, and audio playback from 24 to 30 hours. Ratings for 3G browsing and talk time are unchanged, as the baseband processor that handles the intensive work of communicating with 3G data networks is independent from the general purpose ARM processor. Apple has bumped up rated 2G GSM talk time from 10 hours to 12.
SGX is for graphics
Just as ARM processor cores are the most widely used in mobile devices, Imagination Technology's PowerVR graphics cores are also extremely popular in embedded appliations, commonly appearing as integrated together with an ARM processor on System on a Chip (SoC) devices.
PowerVR started out in the late 90s as a rival to 3dfx in the desktop PC graphics processor market, with both makers also vying for inclusion into the Sega Dreamcast video console in 1998. However, by 2001 the company's third generation PowerVR began falling behind rival products from ATI and NVIDIA.
Imagination subsequently withdrew from the desktop market to focus on embedded graphics components with its highly efficient PowerVR MBX technology, which, like ARM, the company has widely licensed to a variety of device makers, including Apple.
The latest technology generation is branded PowerVR SGX. Anandtech reports that the new graphics architecture improves over MBX in part in that "pixel, vertex and geometry instructions are executed by a programmable shader engine, which Imagination calls its Universal Scalable Shader Engine (USSE)."
The report also states that Imagination's new SGX graphics cores range "from the PowerVR SGX 520 which only has one USSE pipe to the high end SGX 543MP16 which has 64 USSE2 pipes (4 USSE2 pipes per core x 16 cores). The iPhone 3GS, I believe, uses the 520 - the lowest end of the new product offering." It has not yet been confirmed what version of the SGX design the new iPhone 3G S uses.
However, the report noted that "in its lowest end configuration with only one USSE pipe running at 200MHz, the SGX can push through 7M triangles per second and render 250M pixels per second. That?s 7x the geometry throughput of the iPhone 3G and 2.5x the fill rate. Even if the SGX ran at half that speed, we?d still be at 3.5x the geometry performance of the iPhone 3G and a 25% increase in fill rate. Given the 65nm manufacturing process, I?d expect higher clock speeds than what was possible on the MBX-Lite. Also note that these fill rates take into account the efficiency of the SGX?s tile based rendering engine."
Apple's video introduction of the new phone indicates significantly faster launching of and switching between applications and speedier browser rendering and other operations. Overall the company indicates up to a 2x performance improvement.
The use of the Cortex-A8 core has been cited by multiple sources, including an analysis by AnandTech. This makes the new iPhone 3G S very similar in terms of processor design to the Palm Pre, although Palm's phone uses a device built by Texas Instruments.
ARM Processors
The Cortex-A8 is a seventh generation CPU core design licensed by ARM to a variety of manufacturers. The vast majority of all smartphones, handheld games and other mobile devices use ARM processors.
The Cortex-A8 class is referred to in general terms as ARMv7, not to be confused with ARM7, which was actually a third generation ARMv3 used in the Apple eMate300 a decade ago. Previous generations of iPhone and iPod touch used an ARM11 processor, part of the ARMv6 generation.
Apple partnered with its British equivalent Acorn in the late 80s to adapt Acorn's RISC processor for use in mobile devices, forming the ARM partnership. Apple subsequently used a third generation ARM6 in its first Newton MessagePad in the early 90s.
By the time the company discontinued its Newton and eMate devices in 1998, ARM processors had become the most popular mobile processors available, in part due to ARM's licensing of its highly efficient technology to a variety of chip manufacturers. Steve Jobs sold batches of Apple's shares in the ARM partnership at a huge profit to help keep the company afloat.
When the company introduced the iPod in 2001, it used a fourth generation ARM7TDMI processor. The latest generations of the AirPort Extreme also use an embedded ARM processor.
S is for speed
The Cortex-A8 in the iPhone 3G S sports "a two-issue in-order core, capable of fetching, decoding and executing two RISC instructions in parallel," according to AnandTech's report, which also notes, "the ARM11 processor in the iPhone/iPhone 3G has a basic vector floating point unit, but the A8 adds a much more advanced SIMD engine called NEON. The A8 also has twice as many double precision FP registers as the ARM11."
"The combination of higher clock speeds, more cache and a dual-issue front end results in a much faster processor," the report states. "Apple claims the real world performance of the iPhone 3GS can be up to 2x faster than the iPhone 3G, and I believe that?s quite feasible."
The report states that if the processor is running at 600MHz, it would draw three times the power of existing iPhone processors, but notes that in typical use, the device spends a lot of time in standby. Separately, Apple has detailed technologies for maximizing the performance of a processor by running it at less than its top rated clock speed while scheduling tasks more efficiently. This was done with the original iPhone.
As a result of new efficiency measures, Apple claims significantly longer battery life over the current iPhone 3G when using the iPhone 3G S for general processing tasks despite the big leap in performance and the extra power consumed.
Apple has increased the maximum rated battery life of the iPhone 3G S in WiFi internet browsing from 6 hours to 9 hours, video playback from 7 to 8 hours, and audio playback from 24 to 30 hours. Ratings for 3G browsing and talk time are unchanged, as the baseband processor that handles the intensive work of communicating with 3G data networks is independent from the general purpose ARM processor. Apple has bumped up rated 2G GSM talk time from 10 hours to 12.
SGX is for graphics
Just as ARM processor cores are the most widely used in mobile devices, Imagination Technology's PowerVR graphics cores are also extremely popular in embedded appliations, commonly appearing as integrated together with an ARM processor on System on a Chip (SoC) devices.
PowerVR started out in the late 90s as a rival to 3dfx in the desktop PC graphics processor market, with both makers also vying for inclusion into the Sega Dreamcast video console in 1998. However, by 2001 the company's third generation PowerVR began falling behind rival products from ATI and NVIDIA.
Imagination subsequently withdrew from the desktop market to focus on embedded graphics components with its highly efficient PowerVR MBX technology, which, like ARM, the company has widely licensed to a variety of device makers, including Apple.
The latest technology generation is branded PowerVR SGX. Anandtech reports that the new graphics architecture improves over MBX in part in that "pixel, vertex and geometry instructions are executed by a programmable shader engine, which Imagination calls its Universal Scalable Shader Engine (USSE)."
The report also states that Imagination's new SGX graphics cores range "from the PowerVR SGX 520 which only has one USSE pipe to the high end SGX 543MP16 which has 64 USSE2 pipes (4 USSE2 pipes per core x 16 cores). The iPhone 3GS, I believe, uses the 520 - the lowest end of the new product offering." It has not yet been confirmed what version of the SGX design the new iPhone 3G S uses.
However, the report noted that "in its lowest end configuration with only one USSE pipe running at 200MHz, the SGX can push through 7M triangles per second and render 250M pixels per second. That?s 7x the geometry throughput of the iPhone 3G and 2.5x the fill rate. Even if the SGX ran at half that speed, we?d still be at 3.5x the geometry performance of the iPhone 3G and a 25% increase in fill rate. Given the 65nm manufacturing process, I?d expect higher clock speeds than what was possible on the MBX-Lite. Also note that these fill rates take into account the efficiency of the SGX?s tile based rendering engine."
Apple's video introduction of the new phone indicates significantly faster launching of and switching between applications and speedier browser rendering and other operations. Overall the company indicates up to a 2x performance improvement.
Comments
http://www.willitblend.com/videos.as...e&video=iphone
I think we're entering a period where ARM and PowerVR technologies actually start accelerating in development, over the past decade where ARM7/9/10/11 have appeared slowly with minor improvements. Out of order A9 and multi-core will be here next year, Qualcomm have a custom design with dual-core already in their Snapdragon product, Apple appear to be developing their own product that is presumably more than a SoC - i.e., the ARM implementation will be custom or highly tweaked. Marvell's evolved StrongARM in the Sheeva processor is over a GHz already and cheap.
I can definitely see Apple moving OS X based products that aren't computers over to this architecture - the AppleTV surely one day will be on an ARM base, although they might go via a Pineview (Intel Atom + PowerVR SGX530 design) first (it's well overdue for an overhaul and cost reduction).
I can definitely see Apple moving OS X based products that aren't computers over to this architecture - the AppleTV surely one day will be on an ARM base, although they might go via a Pineview (Intel Atom + PowerVR SGX530 design) first (it's well overdue for an overhaul and cost reduction).
I think Atom + Tegra is more likely for the next AppleTV.
But then I realized I may rue the purchase when the iPhone 3GSX is released in 2010... Can't win with tech!
I don't understand why Apple doesn't just outright publish these specs on their web site like they do for desktop systems. Instead we have to poke and prod and tear apart a device for confirmation. People, like me, care about what's under the hood.
I think Atom + Tegra is more likely for the next AppleTV.
Not likely. There's no need for x86 binary compatibility with the ATV. It doesn't run much beyond what's offered with ARM based OS X. If Apple has an architectural license for ARM and has invested 5 million in Imagination there's no way their going with product designed by "Johnny come lately" Intel and Nvidia for low power.
Thanks for the article.
I think we're entering a period where ARM and PowerVR technologies actually start accelerating in development, over the past decade where ARM7/9/10/11 have appeared slowly with minor improvements. Out of order A9 and multi-core will be here next year, Qualcomm have a custom design with dual-core already in their Snapdragon product, Apple appear to be developing their own product that is presumably more than a SoC - i.e., the ARM implementation will be custom or highly tweaked. Marvell's evolved StrongARM in the Sheeva processor is over a GHz already and cheap.
I can definitely see Apple moving OS X based products that aren't computers over to this architecture - the AppleTV surely one day will be on an ARM base, although they might go via a Pineview (Intel Atom + PowerVR SGX530 design) first (it's well overdue for an overhaul and cost reduction).
Apple didn't buy PA Semi and engage in expensive chip design to send their money to a 3rd party. With Imagination they not only get license to use PowerVR SGX but they can also use the VXE and VXD video encoder and decoder chips.
The AppleTV could easily play 1080p content with the appropriate Imagination VXD chip and it would sip watts as compared to trying to get a GPU to deliver the decoding.
If you ask me, Apple would be more future oriented with this thing, I think their using at least an equivalent SGX 530, though ideally they'd use the latest SGX 543 and the VXD for video playback. Also, why not use the much better A9? It's been available for at least a year. It has out-of-order processing and better power efficiency which would account for the better battery life.
That's what I'd do, Apple seems to update hardware every 2 years, or at least that's the trend I see happening. If they need this hardware to last two years, they should be using faster A9s and SGX 530s.
I'm not sure if Anandtech's assessment is correct. If Apple wants to take on Palm, they'd at least use the same level of technology as Palm's Pre. The Pre has a faster SGX 530 and a Cortex-A8.
If you ask me, Apple would be more future oriented with this thing, I think their using at least an equivalent SGX 530, though ideally they'd use the latest SGX 543 and the VXD for video playback. Also, why not use the much better A9? It's been available for at least a year. It has out-of-order processing and better power efficiency which would account for the better battery life.
That's what I'd do, Apple seems to update hardware every 2 years, or at least that's the trend I see happening. If they need this hardware to last two years, they should be using faster A9s and SGX 530s.
Apple will defer to more power efficient designs generally. Since they are never going to laude the specs publically there's no reason for them to play spec one upmanship. It appears that the iPhone may be superior to the Palm Pre in battery life and if that's the case they will have wins in two areas
1. More mature platform
2. Longer battery life
That will be hard for anyone to overcome unless they are twice and good.
I'm not sure if Anandtech's assessment is correct. If Apple wants to take on Palm, they'd at least use the same level of technology as Palm's Pre. The Pre has a faster SGX 530 and a Cortex-A8.
If you ask me, Apple would be more future oriented with this thing, I think their using at least an equivalent SGX 530, though ideally they'd use the latest SGX 543 and the VXD for video playback. Also, why not use the much better A9? It's been available for at least a year. It has out-of-order processing and better power efficiency which would account for the better battery life.
That's what I'd do, Apple seems to update hardware every 2 years, or at least that's the trend I see happening. If they need this hardware to last two years, they should be using faster A9s and SGX 530s.
you don't know why apple chose the hardware they did. heat, battery life etc? spec whores are never happy. as long as it is "teh snappy" and has decent battery life, that's fine by me.
laugh out loud @ apple taking on Palm. try the other way around.
Very nice article and good information.
I don't understand why Apple doesn't just outright publish these specs on their web site like they do for desktop systems. Instead we have to poke and prod and tear apart a device for confirmation. People, like me, care about what's under the hood.
aw, everyone has so much more fun playing detective like this! being spoon fed all the info is no challenge.
Apple's well-known "cult of secrecy" is a product of their also well-known arrogance. but it is a very clever marketing strategy too. all that speculating and guessing and investigating in the blogsphere and media helps to support and hype its additionally well-known "reality distortion field," not to mention its products.
i think we all have a list of questions about Apple stuff we just can't find answers to. life's mysteries ...
Apple will defer to more power efficient designs generally. Since they are never going to laude the specs publically there's no reason for them to play spec one upmanship. It appears that the iPhone may be superior to the Palm Pre in battery life and if that's the case they will have wins in two areas
1. More mature platform
2. Longer battery life
That will be hard for anyone to overcome unless they are twice and good.
exactly right. the Pre's big hardware weak spot is poor battery life. that's a major issue for most, if not all, consumers.
I believe we still have more juice to squeeze out in the software department. But i think that is going to take another 2 years or so of refining. Because finally they are not trying to find the best method, the safest method, most convenient method etc... but the most power efficient method to code their OS and apps... and i think that will take a bit more time. iPhone OS is first step in that direction.
It'll probably coincide with their custom SoC designs. I'm gonna guess that Apple's going to differentiate themselves in power management. ARM is known to be a very efficient core but what's going to separate the "men from the boys" is going to be getting that extra 10-20 %.
Next year they'll probably move to AMOLED and it could be the first line of products using their own designed chips or that could come this year.
I believe Apple will be designing a class of hardware that sits smack dab in the middle of today's hardware.
Look at the talent they've added in just the last year.
Mark Papermaster - PPC boy genius
Ivan Krstic - Security mastermind
Bob Drebin - AMD/ATI graphics guru
Raja Koduri - another AMD/ATI graphics stalwart
It's like watching the Yankees clean up in free agency.
These hires aren't just about the iPhone. These hires about making the Mac a graphics powerhouse "soup to nuts" iPhone to iMac.
The brilliant part is the tech press at large doesn't even see, which means they fail to comprehend, the end around that Apple's doing with Intel.
It'll probably coincide with their custom SoC designs. I'm gonna guess that Apple's going to differentiate themselves in power management. ARM is known to be a very efficient core but what's going to separate the "men from the boys" is going to be getting that extra 10-20 %.
That is a good point. While these new CPUs (ARM, C2D, Atom) are touted as being energy efficent for their classes, and Apple can?t do much about that, there are lot of other chips they can make more efficient. That really is how Apple will shine.
Let's wait and see what the real-word performance is. If the iPhone 3Gs video is any indication, iPhone beats Pre hands down, no matter what the specs are. Remember, Apple's strength is the whole package. As mentioned several times above, there is a reason Apple does not advertise the specs. What matters is the user experience. I had an opportunity to play with Pre for 2-3 minutes. It does not feel faster that the current iPhone. May be there were more apps started or else, but I have a feeling the iPhone 3Gs will come out as a definite winner here.
Even with a slightly less capable GPU the OS X still trumps anything WebOS can do. I think there approach with WebOS and their Mojo SDK is great, since it?s opposite of how Apple is doing things and it?s allowing them to get in the mix faster but we are kidding ourselves if we think the Palm Pre will trounce Apple in any real graphic capability at this point. I?ve read their developer APIs don?t even tie to the GPU at this point. It?s like buying a formula one racer and then putting my grandmother behind the wheel, it?s highly capable HW but you know she?ll just be 25mph around the track with turn signal* on in the wrong direction the whole time.
* She had a turn signal added for the example.
Even with a slightly less capable GPU the OS X still trumps anything WebOS can do. I think there approach with WebOS and their Mojo SDK is great, since it?s opposite of how Apple is doing things and it?s allowing them to get in the mix faster but we are kidding ourselves if we think the Palm Pre will trounce Apple in any real graphic capability at this point. I?ve read their developer APIs don?t even tie to the GPU at this point. It?s like buying a formula one racer and then putting my grandmother behind the wheel, it?s highly capable HW but you know she?ll just be 25mph around the track with turn signal* on in the wrong direction the whole time.
* She had a turn signal added for the example.
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