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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spdfreak - Monday, May 7, 2012 - link
Display model at the BB here in Douglasville, GA was running 5.1 so I guess it is the newer model?BlazeEVGA - Friday, May 4, 2012 - link
"It's also only available in a single capacity." Please clarify...
MorphiusFaydal - Monday, May 7, 2012 - link
The iPad 2 (post new iPad release) is only available as a 16 GB WiFi-only model. So it's only available in a single capacity.shompa - Friday, May 4, 2012 - link
Why do all believe that smaller process nodes decreases the cost of manufacture the chips? Yes: You can fit more die candidates on a smaller process node, but the wafer price is raised for each new processor node.Only of you own you own fabs and don't count the migration cost from one node to another node you are guaranteed a cheaper price per node shrink.
shompa - Friday, May 4, 2012 - link
Apple must have hired hundreds/maybe thousand of people working on their SoCs. PA Semi + more.To make a new tapeout/masks for exactly the same processor that is used today. I can't recall that in history.
If we believe the rumors that Apple got test wafers from TSMC june and october last year, then Apple designed at least 3 SoCs last year.
A5X, A532nm and A6/ARM15.
PeteH - Friday, May 4, 2012 - link
Wouldn't Samsung be responsible for the masks?name99 - Friday, May 4, 2012 - link
"This is nothing new, but it's always interesting to get an idea of the amount of variance Apple considers acceptable."I think it's important to distinguish between variance that Apple considers acceptable (because it doesn't really make a difference) and variance Apple considers acceptable (because what choice do they have?)
I have complained to Apple about how irritating it is to have items that should be consistent (think of contact photos shared via iCloud for example, where the human eye is very sensitive to minute variations) appear different on iMac, iPad, MBA, and iPhone screens; and I suspect Apple is sympathetic to the problem. But screen technology is where it is today, and right now we have to accept these sorts of variations as part of the deal (different companies, different processes, lots of experimentation) that gives us really amazing quality screens for just a few hundred dollars each. Maybe in ten years we'll be in a position to deliver a single consistent screen appearance across the entire product line.
(And as for people who think complaining that contact photos look different on different screens is the height of pettiness: perhaps there's a reason that the one company that appears to care about these minor details is ALSO the one company that's making money hand over fist in this area?)
Reflex - Friday, May 4, 2012 - link
Was this a comparison of a brand new iPad 2,1 to a brand new 2,4? I ask because the 15% gain seems dubious when the CPU is such a tiny portion of the overall power budget. What I do know is that over time LiON batteries lose their charge capacity, so comparing a year old iPad2 to a brand new iPad2 would show the new one as having better battery life even if they had identical internal hardware.Did I miss this in the review?
Anand Lal Shimpi - Friday, May 4, 2012 - link
I got this question via email as well:All of the tests were re-run on a newer but not brand new iPad 2, with very few charge cycles (< 20) on the battery. I also ran a test comparing battery life of the older iPad 2 at new vs. when tested and showed no measurable decrease in battery life (you can actually see that video playback battery life hasn't changed even compared to our original iPad 2 review). Finally, the power consumption results remove the battery from the equation and validate the difference in power.
The web browsing test is going be primarily dominated by display, followed by SoC power consumption. Keep in mind that even when the CPU cores aren't busy parsing HTML and running javascript, leakage is still a problem - Samsung is promising a ~10x decrease in leakage from the move to 32nm.
Take care,
Anand
Reflex - Friday, May 4, 2012 - link
Thanks for the reply, its appreciated.