One of the longest coming announcements at CES 2012 was the unveiling of Intel’s Medfield platform, a mobile system-on-a-chip (SoC) to compete with ARM. This component is going to kick off an era of Android on x86 when all the mainstream mobile operating systems have thus far been ARM-only. With Intel’s reentry into mobile chips, we could finally see some competition to drive down prices and encourage a new wave of innovation.
Let’s take a look at what x86 will mean for Android, and try to decide is this is a winning strategy.
Medfield Atom Z2460
Intel’s first offering to actually go into phones will be the Atom Z2460, so to adequately assess Intel’s chances, we need to see how this part stacks up. The Medfield platform is the successor to Moorestown, but better tuned to work in today’s high-end mobile devices. The SoC itself is called Penwell, and it pairs a 1.6GHz Atom CPU (Saltwell core) with a familiar SGX540 GPU. This is the same GPU from the Galaxy Nexus. The SoC taken together with radios, cameras, and the rest is the Medfield platform.
Intel’s new mobile part comes only in a single-core variety, but ARM makers are currently engaged in a multi-core race. If you talk to people that build mobile products and software, they will often tell you that the number of cores matters less than most consumer might like to think. Atom has an advantage in that it is very fast for single threaded applications. When software is specifically designed to take advantage of it, Medfield’s Hyper-Threading can offer performance improvements without the power required by a second physical core.
Medfield’s Saltwell CPU core is built with a 32nm manufacturing process, which is smaller than most of the shipping Atom parts we have now. 32 and 28nm processes will begin showing up in ARM later this year. The new Saltwell architecture also lets the processor clock itself up and down very quickly, in as little as 70ms after needs change. It can run as low as 100MHz for processing background tasks.
Intel has been working on getting Android ported to x86 for some time now, but the community was already in place; the x86 Project has been porting Android for the last few years. The issues involved are non-trivial, but Intel has a lot more muscle to get the hard work done. We have no doubt that Intel can make Android work on its chips more fluidly than the x86 Project has so far.
While Intel will have to get its hands dirty helping OEMs supporting its new platform, Google isn’t standing on the sidelines. Back in September, the two companies announced an alliance to make sure Android works on Intel chips. The operating system itself should run natively on Atom when the first devices ship, but we worry that the additional work of building updates for the new architecture could delay their rollout, at least at first.
Another potential problem is that of apps. Even if Android itself is completely ready to go on x86, there is no guarantee that all Android apps will be ready. Most apps are written in Java and should be fine. These apps are run through the Dalvik virtual machine, which compiles them to bytecode for execution. The problems arise when apps, or sometimes just parts of apps, are written in native code.
Roughly a quarter of Android apps make use of native code, and many of them are games. Part of Intel’s efforts have been directed at designing a binary translator that will process native code such that it can be run by the x86 part. Essentially, this is like inserting a virtual machine in between the native code and the hardware. The resulting slowness is exactly why these apps are written in native code and not Java in the first place.
Intel is working with top developers to make sure that apps work as intended on its Medfield platform. The chip-maker estimates that 90% of Android apps will be operational on Atom by the time the first devices launch. Although, we have to wonder if that 90% includes native apps that are just running through the code translator. If that is the case, many graphically intensive apps will not provide a good experience when compared to ARM.
Something Android has always had trouble with is power usage. Google added some more advanced power monitoring back in version 2.3. If Atom could bring some improvements in this respect, users might overlook that potential app compatibility situation. In its admittedly early form, Intel's provided power draw numbers are quite good in some areas.
Medfield web browsing on Android draws 1W of power; not bad when you consider that the Exynos chip in the Galaxy S II pulls 1.2W. At this time, that’s really the best of it, though. Other tasks are a little more power intensive; for instance, 720p video playback consumes 850mW on Medfield, but just 650mW on the Galaxy S II.
These numbers are good, not great, and they come when comparing a 32nm Intel part to a 45nm Samsung one. When ARM parts undergo the 2012 process shrink to 32nm, Intel’s Atom chip might start to look like it is standing still by comparison.
Everything we know about Atom right now tells us that it is at least in the same ballpark as ARM. This move will get Intel a seat at the table once reserved for the likes of Texas Instruments and Qualcomm. This is the first step, a way to prove that Intel can do more than laptop and desktop chips. With a planned process shrink to 22nm in 2013, Intel is making it clear that it won’t walk away from mobile this time.