Android on x86: A quick look at Asus’ Memo Pad ME176C tablet
Remember when people dismissed the iPad as a fad? It’s just a big iPod Touch, they said. Who would want one of those?
Quite a lot of folks, actually. The iPad touched off a revolution that has grown to truly epic proportions. 207 million tablets shipped last year, according to market research firm Gartner, and that total is expected to grow to 256 million in 2014. The following year, Gartner projects that tablet shipments will hit 321 million units and eclipse PCs for the first time.
So, yeah, probably not a fad.
Intel initially missed the boat on the tablet trend, but it’s starting to make inroads in the market. In an earnings press release issued last week, CEO Brian Krzanich said the company is on track to ship in 40 million tablets this year. Many of those devices will likely be smaller, inexpensive Android slates like Asus’ Memo Pad ME176C.
At a glance, it’s easy to see why Intel expects to move a lot of tablets like these. The Memo Pad sells for just $149, yet it has a quad-core Bay Trail SoC, a 7″ IPS display, and a nice selection of additional features. Looks like a great deal, right?
Maybe. You see, those Bay Trail cores might be great for Windows PCs, but they’re based on an x86 instruction set architecture (ISA) that’s sort of a foreign language in the mobile world. Most tablets use ARM-compatible chips with a completely different ISA. Any apps with ARM-specific code must be adapted or translated just to run on x86 hardware, which could lead to slower performance and longer load times.
The obvious question, then, is how does Intel’s latest Atom fare on an Android device? More importantly, can a cheap Bay Trail tablet like the Memo Pad ME176C deliver a good user experience? I’ve been using one to find out, and the answers are a little complicated. Allow me to explain.
Anatomy of a budget slate
Some aspects of the Memo Pad are easy to grasp. Take the Atom Z3745 SoC, for example. It’s an Android-specific version of the Bay Trail quad found in Asus’ $350 Transformer Book T100 convertible. The CPU cores have the same 1.33GHz base and 1.86GHz Burst frequencies, and the base GPU speed is unchanged. The peak GPU clock is 111MHz higher, though, at 778MHz.
|Processor||Atom Z3745 (1.33GHz base, 1.86GHz Burst)|
|Graphics||Intel HD Graphics (311MHz base, 778MHz Burst)|
|Memory||1GB LPDDR3 1066|
|Display||7″ IPS panel with 1280×800 resolution (216 PPI)|
Up to 64GB via Micro SD
|Ports||1 Micro USB
1 analog headphone/microphone
|Cameras||5MP rear, 2MP front|
|Dimensions||7.5″ x 4.5″ x 0.38″ (190.5 x 114.3 x 9.65 mm)|
|Weight||0.65 lbs (295 g)|
The Memo Pad runs Android 4.4.2, otherwise known as KitKat. This OS revision includes optimizations for devices with lower memory capacities, so the gig of system RAM shouldn’t be a huge handicap. Neither should the 16GB of internal flash, which is comparable to the base storage capacity of premium Android and iOS slates. Unlike a lot of those pricier tablets, the Memo Pad has a Micro SD slot ripe for secondary storage. Up to 64GB can be added via mini memory card.
A Micro USB connector and headset jack are the only ports of note. There are dual cameras, of course—a 5MP unit at the rear and a 2MP one up front—plus 802.11 Wi-Fi, Bluetooth, GPS, and the usual collection of sensors. Power and volume buttons grace one edge, but their arrangement is a little unusual. The power switch sits below the volume rocker, which is the opposite of how things are organized on the Nexus 7 and most other Android tablets we’ve used.
Despite its bargain price tag, the Memo Pad doesn’t feel overly cheap. The back is draped in smooth, soft-touch plastic that has just enough grip to keep the tablet from slipping out of my hands. This matte finish isn’t completely impervious to smudges and fingerprints, but neither is the glossy touchscreen on any tablet. I’m over it.
The build quality appears to be solid overall. The frame is fairly stiff, with minimal flex and no obvious creaking when the body is torqued. I don’t have the guts to do a drop test, though.
The display is based on a 7″ panel with a 1280×800 pixel array. That resolution is a decent fit for the screen size, though it obviously doesn’t match the crispness of higher-PPI alternatives like the latest Nexus 7. Text and images still look reasonably sharp, and individual pixels aren’t visible unless you hold the tablet right up to your face. Picky reviewers are probably the only ones who will ever get that close to the screen.
We haven’t had time to run the screen through our usual, ahem, gamut of colorimeter tests. However, the output looks good to my eyes, with vivid colors, wide viewing angles, and no obvious signs of backlight bleed. As an added bonus, the picture can be tuned with Asus’ Splendid software, which has sliders for color temperature, hue, and saturation. The brightness can also be adjusted, but only manually. The Memo Pad lacks the ambient light sensor required for automatic backlight control.
Everything is squeezed into a compact chassis that’s 0.38″ (9.6 mm) thick and 0.65 lbs (295 g). Slimmer tablets do exist, but I think we’ve reached the point where shaving a couple more millimeters doesn’t make a big difference. The Memo Pad is easy to carry and hold with one hand, just like every other 7″ tablet I’ve used. The battery life seems to be comparable to that of other contenders, too. Asus claims run times up to nine hours on a single charge, which matches my subjective impressions based on casual use.
Multiple paths to x86 compatibility
Bay Trail’s x86 pedigree may be at odds with the predominant ISA for mobile devices, but the situation isn’t as dire as one might expect. Intel has been working with Google on Atom-specific Android tweaks since 2011. The CPU giant has contributed code to the Android kernel and libraries, and it’s validated and optimized device drivers to work with x86 hardware. At the OS level, at least, the Atom’s x86 roots shouldn’t be an issue.
The situation with applications is a little different. Most Android apps run in Dalvik, a virtual machine that’s isolated from the OS. The code is typically written in Java, and it’s compiled only when the program is launched. Dalvik can generate x86 instructions, so there shouldn’t be any problems with these kinds of apps.
Instead of relying Dalvik’s just-in-time approach, some Android apps use pre-compiled binaries generated by the Native Developer Kit (NDK). The NDK supports other languages, such as C and C++, and it can target different ISAs, including ARM and x86. As I understand it, generating an x86 binary from an NDK project involves little more than clicking a checkbox. I’m not a programmer, though; the process may be more complicated than that. In any case, Intel has a full suite of resources to help developers build native x86 apps using the NDK.
If apps lack x86 binaries or are otherwise tied to ARM-specific code, binary translation is used to transform ARM instructions into x86. This software-based emulation layer should be invisible to end users, but there’s some unavoidable overhead involved. Naturally, Intel and ARM disagree on the impact of that overhead. Intel claims the effect is minimal in most applications, while ARM warns of slower application load times, increased stuttering in games, lower overall performance, and reduced power efficiency.
The argument may end up being moot, because Google recently introduced a new Android runtime environment, dubbed ART, that will replace the Dalvik VM in future versions of the OS. (ART is available in an experimental capacity in the current KitKat release.) This new environment ditches Dalvik’s just-in-time approach for pre-compiled code that’s supposed to improve performance. Given Intel’s previous contributions to Android, ART should be well-optimized for x86 CPUs.
Right now, gauging the impact of binary translation is somewhat difficult because Android apps generally don’t advertise their x86 credentials. APK files can be searched for telltale binaries, but that’s a little involved for a quick-take piece like this one. Measuring application performance in Android is tricky enough without having to deal with different ISAs.
For the Memo Pad ME176C, we elected to combine a handful of common benchmarks with load-time tests and real-world usage impressions. That should provide a sense of how the tablet behaves even if it doesn’t answer some of the deeper questions about how well x86 processors deal with ARM-optimized code.
Let’s start with the benchmarks, which compare the Memo Pad to a selection of mobile devices running Android and Windows. The graphs have been colored by operating system, with our subject set apart from the rest of the Android pack.
Note that the Memo Pad nearly matches the Transformer T100, which is based on a similar SoC running Windows. At least in these tests, there doesn’t appear to be too much of a penalty associated with Android.
Next, we’ll look at graphics performance in 3DMark’s “Ice Storm” test. To compensate for devices with different resolutions, this benchmark renders scenes offscreen at 1280×720 before scaling the output for the target display.
Bay Trail’s graphics horsepower appears largely intact on Android. Although the T100’s advantage is wider in this test, the Memo Pad isn’t too far behind. And it’s still ahead of the current Nexus 7.
For this next batch of tests, we recorded application load times with a high-speed camera capturing 240 frames per second. We used popular apps and tried to avoid ones that grab a lot of Internet content on startup.
Interesting. The Memo Pad loads our selection of games slower than both Nexus tablets. The differences are especially apparent in Clash of Clans, where the Memo Pad trails even the old Nexus 7 by more than five seconds.
Don’t act like you weren’t curious about Kim Kardashian Hollywood load times.
These other apps load much faster overall, and the Memo Pad leads the competition in three of four tests. The differences only amount to about a second at most, though. They’re usually much slimmer than that, especially between the Memo Pad and the Snapdragon-powered Nexus 7.
For what it’s worth, we observed more run-to-run variance in Skype and YouTube load times than we did in the other tests, probably because those apps pull content off the ‘net.
Living with Android on x86
To evaluate how well the Memo Pad ME176C works in the real world, I’ve been lugging our sample around like a digital security blanket. The thing barely leaves my side while I’m at home. I’ve grown a little attached, to be honest, but I’ve also become acutely aware of the device’s shortcomings.
For the most part, the tablet delivers a good user experience. The UI is responsive, web pages render quickly, and games look good and run fluidly. I rarely feel like I’m waiting on the device—until I start multitasking. The Memo Pad tends to bog down when more than a few apps are running, likely due to its limited system memory. Trimming the number of concurrent apps quickly brings the tablet back up to speed, so the slowdown isn’t crippling. Power users are likely to be disappointed, though, especially if they’ve experienced the Nexus 7’s more consistent snappiness.
Apart from a few crashes in GT Racing 2, my testing has been entirely free of quirks—no compatibility issues, application glitches, or graphical artifacts. The Memo Pad’s Wi-Fi reception isn’t great, but that’s my only other real complaint. Well, that and the fact that Asus’ ZenUI Android skin replaces the usual six icons at the bottom of the screen with four oversized ones. Fortunately, ZenUI otherwise sticks closely to the standard Android script. Its configurable Quick Settings menu is a nice addition, and Asus’ File Manager utility is excellent.
All things considered, the Memo Pad ME176C is pretty good given the $149 asking price. It feels kind of like the netbook of tablets: a decent solution for folks looking to cover the basics on a tight budget. That seems rather appropriate given the Atom underpinnings. After all, Intel’s low-power CPU rose to fame in netbooks, which undercut the pricier ultraportables of their time.
Back in that era, the Atom stole market share away from Intel’s more premium processors. Now, it’s being used to gain a foothold in hostile territory. Intel is basically paying tablet makers to use its processors. That strategy seems destined to increase the installed base of x86 chips running Android, which should encourage mobile developers to make sure their apps work well with that ISA. If that means more cheap, capable tablets for consumers, I can’t complain.