The iPad 2,4 Review: 32nm Brings Better Battery Life
by Anand Lal Shimpi on May 4, 2012 12:50 AM ESTFinal Words
If Apple's A5 is any indication, Samsung's 32nm HK+MG process is extremely capable. Assuming Apple didn't change any fundamentals of its microarchitecture, the iPad 2,4's gains in battery life can be attributed directly to the process. The gains themselves are significant. We measured a 15% increase in our web browsing battery life, a nearly 30% increase in gaming battery life and an 18% increase in video playback battery life. Although Apple hasn't revised its battery life specs, the iPad 2,4 definitely lasts longer on a single charge than the original iPad 2.
If you're in the market for an iPad 2, the 2,4 is clearly the one to get - if you can find one that is. Unfortunately there's no sure fire way to tell that you're getting a 2,4 without opening the box and turning on the tablet, and I suspect most stores will get a bit irate if you're constantly buying and returning iPad 2s in search for a 32nm model. Presumably over time more of the available inventory will shift to 2,4 models, but based on our experiences in trying to find a 2,4 it's still pretty tough.
I would like to applaud Apple's 32nm migration plan. By starting with lower volume products and even then, only on a portion of the iPad 2s available on the market, Apple maintains a low profile and gets great experience with Samsung's 32nm HK+MG process. It's very clear that this is all in preparation for the next iPhone, which will almost certainly use Samsung's 32nm process and require it in significant volumes. It's obvious that Apple employs some very smart chip heads in Cupertino.
What I'd really like to see is a 32nm version of the A5X used in the new iPad. I don't know that there's much reason for that this year, especially when the 4th generation iPad will likely ship in the first half of 2013 with yet another new SoC (dual-core A15 + Rogue anyone?), but it'd still be nice to have. The power efficiency improvements are substantial and the 3rd gen iPad could definitely use them. Those of you who are waiting for the next iPhone should also be pretty happy about these results. Apple could easily deliver a higher clocked version of the A5 for the next iPhone while keeping power consumption equal to if not lower than where it's at today. The move to 32nm is going to be good all around it seems, and Samsung appears to be a very capable foundry partner for Apple. Despite all of the rumors of a rift in the relationship, the foundry side of things is working out well.
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PeteH - Friday, May 4, 2012 - link
Was video testing done full screen or letterboxed? Assuming it was done letterboxed, is it possible that backlighting of the display can be selectively turned off near the top and bottom of the screen? That would definitely save power.It'd be easy enough to test. Just run the test full screen and see if the playback time changes.
dagamer34 - Monday, May 7, 2012 - link
Backlight works across the entire display. There is no local dimming.jjj - Friday, May 4, 2012 - link
Not so sure the foundry part is working all that well,they didn't had 32nm for the ipad 3 and they had to cut a few corners without it (huge battery- ads cost , weight and bulk , way hotter , moving the ram on the other side of the PCB ).You put a positive spin on the way they transitioned to 32nm but there is no reason to keep the 32nm part low vol,and not transition all ipad 2 SKUs if Samsung has capacity and yields are good so something might not be quite there just yet. I always thought the ipad 3 on 45nm was a plan B device and Apple having A5 on 32nm this early makes it look even more so.
BSMonitor - Friday, May 4, 2012 - link
Sure there is. Apple has no control of the volume for the A5X if they have TSMC move to a new node and try and build a new SoC on it. We have seen ALL CPU/GPU manufacturers struggle with yield when transitions to new nodes coincide with new designs. So rather risk holding back 30 million iPad 3's to a April, May, June launch, they took the risk of low yields out of the equation and stuck with 45nm.Remember, any transition to a new node for any chip maker is typically a different Fab. And/or retooling existing Fabs. So as new 32nm Fab's come online, they won't be anywhere near the capacity of 45nm Fab's for some time.
We don't mention this much, because Intel has made this seem almost immaterial. But it is a BIG deal, and VERY expensive to ramp new nodes. Look at AMD, this side of the game would have eventually bankrupted them due to the expense of it all.
BSMonitor - Friday, May 4, 2012 - link
Err. Samsung not TSMC.. LOLltcommanderdata - Friday, May 4, 2012 - link
It's not just the iPad 3 that would find a 32nm shrink useful. With it's higher battery consumption, it's interesting that Apple didn't decide to use the 3G iPad 2 as the 32nm A5 testbed. The 3G iPad 2 is also presumably a lower volume product than the WiFi iPad 2 which also works in it's favour as a pilot. Would an SoC change still require a new round of carrier/government radiation testing, since that would be a major disincentive?It's good that you found the performance of the iPad2,4 unchanged. Your previous new AppleTV articles mentioned that it was coupled with a single 512MB LPDDR2 RAM die indicating only a single 32-bit channel memory configuration. It looks like the 32nm A5 in the iPad 2,4 implements the full 2x64-bit memory system.
Given the smartphone GPU performance showing in the Exynos 4412, if Apple wants to regain the GPU performance crown and hold it into 2013 when Rogue shows up, they'll probably need to be more aggressive than an up-clocked 32nm A5 in the iPhone 5. The 32nm A5 looks like a shoe-in for the next iPod Touch though.
André - Friday, May 4, 2012 - link
Why?Everything in iOS is synced to 60Hz, which SGX543MP2 already does at 960 x 640.
Sure you could always add more eye candy.
gevorg - Friday, May 4, 2012 - link
Not sure why Apple would be so conservative about rolling out the 32nm process with such a limited run for more than half of 2012, while Samsung just released their Galaxy S3 build on 32nm and ready to sell like hotcakes.KoolAidMan1 - Friday, May 4, 2012 - link
Apple is selling every single iPad that they make. Potential supply constraints from a new process is a huge risk to take. Low initial yields are a common bottleneck for new products, look at what is happening with the GTX 680 right now.They weighed the pros and cons and decided to go with what is proven, tradeoff being the absolutely massive A5X SoC.
Also note that new iPad production started late last year. Just a few months makes quite a difference, which is why we'll soon be seeing 32nm in upcoming smartphones.
BSMonitor - Friday, May 4, 2012 - link
Actually, the Galaxy S3 accounts for a fraction of the new Ipads necessary for its launch.