ARM Compatibility: Binary Translation

Similar to Apple's move from PowerPC to x86, Intel finds itself in a difficult position with bringing Atom to Android. The OS isn't an issue as it has already been ported to x86 and all further releases will be available in both ARM and x86 flavors. The bigger problem is application compatibility.

There's already support for targeting both ARM and x86 architectures in the Android NDK so anything developed going forward should be ok so long as the developer is aware of x86.

Obviously the first party apps already work on x86, but what about those in the Market?

By default all Android apps run in a VM and are thus processor architecture agnostic. As long as the apps are calling Android libraries that aren't native ARM there, once again, shouldn't be a problem. Where Intel will have a problem is with apps that do call native libraries or apps that are ARM native (e.g. virtually anything CPU intensive like a 3D game).

Intel believes that roughly 75% of all Android apps in the Market don't feature any native ARM code. The remaining 25% are the issue. The presumption is that eventually this will be a non-issue (described above), but what do users of the first x86 Android phones do? Two words: binary translation.

Intel isn't disclosing much about the solution, but by intercepting ARM binaries and translating ARM code to x86 code on the fly during execution Intel is hoping to achieve ~90% app compatibility at launch. Binary translation is typically noticeably slower than running native code, although Intel is unsurprisingly optimistic about the experience on Android. I'm still very skeptical about the overall experience but we'll have to wait and see for ourselves.


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  • hechacker1 - Tuesday, January 10, 2012 - link

    What's impressive to me is the fact that you have an Atom, which powers generations of netbooks, running as a SoC using only milliwatts of power most of the time.

    I'd love to see a tablet/netbook version with a huge battery that could run for the better part of a day.

    It would even do really well as a media server/HTPC if only it had I/O bandwidth for hard disks and HDMI outputs with surround sound.
  • aNYthing24 - Tuesday, January 10, 2012 - link

    Not really all that impressed. By the time it's out, you'll start seeing phones ARM Cortex-A15 based SoCs which are about 40-50% faster than Cortex-A9 based SoCs. Reply
  • MonkeyPaw - Tuesday, January 10, 2012 - link

    Yeah, I'm still on the naysayer's side, too. The SOC market isn't as slow to develop as x86. We've seen rapid improvements over the course of the last 4 years. Where the next generation of x86 may get you 15% more performance (if you can even utilize it all), SOC's are gaining in relative leaps and bounds, and the improved performance is quite noticeable. I went from an iPhone3G to an iPhone4, and every aspect of performance was clearly better. Everything loads faster, you can "multitask" and take better pictures and HD video, and the battery life is still better. That was in 3 years time. 3 years from now looks to be just as positive. That means Intel has the tougher road. It took them 5 long years to get Atom DOWN to sub 1W TDP and into a phone, while ARM SOCs have always been working inside this power design.

    That said, I sure as heck hope this doesn't fowl up Android Market any further. I've said it before, App compatibility is already not a given due to OS version fragmentation. Adding x86 will just require more effort on the developer's part, which might doom Intel's early chances anyway.

    Rest assured, Intel will dump billions into this and not go away. They can't afford to miss out on this market. I wonder when AMD will figure that one out...
  • yvizel - Wednesday, January 11, 2012 - link

    Clearly shows how little do you know... WOW. Reply
  • Griswold - Thursday, January 12, 2012 - link

    He may know little, whereas you know NOTHING.

    Back under your rock, peanut.
  • stadisticado - Wednesday, January 11, 2012 - link

    I gotta say...I really disagree with your assessment. ARM SOCs have indeed improved a lot over the past few gens. However, that is largely due to moving to new nodes, going from single to double to quad core uarch and finally in moving up the ladder on ARM architectures. Now, Intel is jumping in here, let's assess along these vectors:

    I don't think anyone is arguing Intel has process leadership, perhaps not in SOC, but at least their 32nm node is competing directly with TSMC 28nm.

    As for the core wars, I predict Intel goes the route they go in laptops: dual core with HT is the right balance of perf/power for most applications. That said, I guarantee we see quad cores with HT for tablets in 2013 on 22nm.

    The uarch question is yet to be answered. Ultimately we'll have to see how A15 stacks up against this single core Saltwell and the dual core that's coming in the Clovertrail platform.
  • name99 - Wednesday, January 11, 2012 - link

    What Intel naysayers (at least the ones that aren't twelve years old) say is that x86 complexity puts SEVERE constraints on how fast Intel can spin these chips around. It took something like 7 years for Nehalem to move from initial design to fully validated and ready to ship.

    Now, in the "traditional" x86 space, this has not been that much of a problem for Intel for a while because they run so much design in parallel, so that each team has its new CPU ready each year. Even so it does occasionally cause problems when Intel misjudges where things will be in the future and misses a feature for a few years. The most obvious example of this was x86-64, but we saw it again regarding moving the memory controller on-die, and regarding how powerful users expect on-chip GPUs to be.

    So, when it comes to Atom:
    (a) do they have multiple design teams in place, so that we can now expect a steady rate of serious improvement every year. Or is this the fruit of their one major design team, and we can expect it to stand still, apart from minor tweaks, for the next three years or so?
    (b) are they willing to modify the SOC as requested by different vendors, to improve power or reduce size? What if I want a custom flash controller on the SOC or a better than average camera processor? Maybe this doesn't matter --- but maybe it does. I think honestly none of us know. What we DO know is that the phone market is different from the old-school PC market. Unlike old school PCs, size (fewer parts) and power (better integrated parts) matter a huge amount, which gives an advantage to CPU vendors who are willing to tailor their SOCs to include anything extra the manufacturer wants, while tossing anything they don't want.

    Finally: "ARM SOCs have indeed improved a lot over the past few gens. However, that is largely due to moving to new nodes, going from single to double to quad core uarch and finally in moving up the ladder on ARM architectures. Now, Intel is jumping in here, let's assess along these vectors:"
    This process (for ARM) has not stopped. ARM-64 is a COMPLETELY new architecture, optimized for power and performance based on everything ARM has learned over the past few years, and tossing various components of the architecture that no longer make sense. ARM-64 devices plan (as far as I know) to be compatible, during the brief period that is necessary, to have a separate ARM-32 core on die to handle ARM-32 binaries --- no crippling of either the ARM-64 architecture or the core design in order to allow 32-bit binaries to still work with it.

    The point is that ARM is both improving their underlying architecture aggressively, AND that they are doing everything they can to ensure that they can remain nimble and easily able to spin out new cores with new ideas as the market evolves. Compare with Intel and their 7 year design cycles...
  • stadisticado - Wednesday, January 11, 2012 - link

    On the 7 year design cycle: How long ago did ARM Holdings start RnD on A15? Whats the cycle time for that product to go from scratch to inside a product? That 7 year cycle you're quoting is literally from the first time the name showed up in a design document to ship, which I don't feel is a good comparative metric, especially for SoCs which share multiple common blocks across gens.

    Does Intel have more design teams on Atom? No idea - but looking at the roadmap they have Atom on they basically have to. One team is not capable of spinning Medfield and pushing the 22nm Atom out the door next year and then 14nm the year after.

    Basically you're stipulating that ARM is inherently faster than Intel in this space. Its yet to be demonstrated but I'm stipulating that is going to turn out to be a bad assumption.
  • PubFiction - Thursday, January 12, 2012 - link

    Intel did not have a good dedication to atom but they are now getting there. So ARM obviously had the advantage before. Intel considered Atom second rate stuff to put on old nodes.

    Also while the design of a full desktop CPU is long from start to finish I do not think it has anything to do with x86. It is more about just competing at the highest end. Itanium was no walk in the park. And so far no other architecture has beat x86. At the very least it still takes anyone else a long time to design chips.

    The reason ARM moves faster is their chips are so much more simple. And atom is moving in that direction.

    Intel is a scary competitor for anyone in any processor space. Once they dedicate to something it will get competitive. Does not mean they will win, but if these chips have this performance and actually do ship this year it they may not beat A15 but they will be good enough to stick in phones. And that is the start intel needs.
  • zeo - Saturday, January 14, 2012 - link

    Yes, Intel had the ATOM on a slow 5 year product cycle but now they are switching it to a 2 year cycle for similar rate of advancement as Intel's higher end chip offerings.

    The 22nm Silvermont update coming out in 2013 will be when the switch is official and we can start expecting the usual year by year tic toc of advancement.

    For example, Silvermont is more than just another die shrink but also the first major architectural change for the ATOM. Like Out Of Order Processing, as well as adding new technology like Intel's Tri-Gate Transistors.

    Intel ATOMs also will be supporting a range of 1 to 8 cores. The 8 core version presently being focused for the server market, but it's likely Intel will leverage multiple cores for most of their intended product lines.

    Cedar Trail is for example dual core for both the high end and low end chip versions.

    While the Clover Trail and Medfield shows Intel is making progress of SoC and improving power efficiency to be at least good enough to start competing in the mobile market.

    Though we still have to see if Intel can be price competitive and Intel will likely need to offer even better performance than ARM can offer with their next gen offerings to start to really expand into the mobile market. So Intel has a lot riding on coming through in 2013.

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