Apple's A5X Die (and Size?) Revealed
by Anand Lal Shimpi on March 15, 2012 5:15 PM ESTiFixit saved us all a whole lot of trouble and performed a teardown of the new iPad announced last week. The internals were mostly what we expected, down to the Qualcomm MDM9600 LTE baseband. Despite many of the new iPad's specs being a known quantity prior to launch, there were a few surprises in the teardown.
First and foremost, Apple has moved away from a PoP (Package-on-Package) stack with the A5X SoC and now uses two discrete DRAM devices. The iPad iFixit took apart featured two 512MB Elpida LP-DDR2 devices on the side of the PCB that doesn't feature the A5X (in yellow, below). The A5 SoC featured a dual-channel (2x32-bit) LP-DDR2 memory interface running at up to an 800MHz data rate.
Elpida, like most DRAM manufacturers, does a terrible job of keeping its part number decoders up to date publicly so these two devices (B4064B2MA-8D-F) aren't well documented. The first character in the part number ("B") tells us that we're looking at mobile/low-power DDR2 memory. The next two characters ("40") typically refer to the device density, the 4 in this case likely means 4Gbit while the 0 is a bit odd since it usually refers to DRAM page-size. It's the fourth and fifth characters that are a bit odd to me ("64"). Usually these tell us the width of the DRAM interface, the 64 would imply something that doesn't appear to be true (initial memory bandwidth numbers don't show any increase in memory bandwidth). It's quite possible that I'm reading the part number incorrectly, so if anyone out there has an updated source on Elpida (and other) DRAM part numbers please do share. Update: The 64 doesn't imply a 64-bit interface as we can see from this datasheet. The two devices are 32-bits wide each, unchanged from A5 implementations. Thanks ltcommanderdata!
As you might have guessed from the fact that Apple now adorns the A5X with a metal heatspreader, Apple has potentially made the shift from a wirebond package to flip-chip. What you're looking at in the shot above with the heatspreader removed is the bottom of the A5X die. If you were to drill down from above you'd see a layer of logic then several metal layers. Moving to a flip-chip BGA package allows for better removal of heat (the active logic is closer to the heatsink), as well as enabling more IO pins/balls on the package itself. Running gold wires from a die to the package quickly becomes a bottleneck as chip complexity increases.
Note that it is possible for Apple to have used flip-chip in the A5 and simply hidden it under the PoP memory stack. Intel's Medfield for example uses a FC-BGA package but will be covered by DRAM in a PoP configuration.
Update: Chipworks has actually measured the A5X die: 162.94mm^2. This means that our visual inspection was inaccurate and Apple is likely still on a 45nm process, which would explain the unchanged CPU clocks. This also helps explain the move away from a PoP stack. At 45nm the A5X's worst case thermals (heavy GPU load) probably demand much better cooling, hence the direct attach heatspreader + thermal paste.
Using the Toshiba eMMC NAND that resides next to the A5X as a reference, we can come up with a rough idea of die size. Based on Toshiba's public documentation, 24nm eMMC 16GB parts measure 12mm x 16mm. Using photoshop and the mystical power of ratios we come up with a rough estimate of 10.8mm x 10.8mm for the A5X die, or 117.5mm^2. If you remember back to our iPad analysis article, we guessed that conservative scaling on a 32nm process would give Apple a ~125mm^2 die for the A5X. While there's a lot of estimation in our methodology, it appears likely that the A5X's die is built on a 28/32nm process - or at least not a 45nm process. Note that this value is entirely dependent on the dimensions of Toshiba's NAND being accurate as well as the photo being as level and distortion-free as possible.
I'll chime in a little later to talk about A5X SoC performance.
Images courtesy iFixit
Facebook
Twitter
RSS
45 Comments
View All Comments
chasm22 - Thursday, March 15, 2012 - link
name99 tell me, with the title of the thread being what it is, what insight did you contribute except that of an Apple fanboy obviously upset that his wonderful company has now launched an iPad and an iPhone whom between them can't list anything new except Siri and a retina display. Whew, I'm breathless. No wonder the stock is soaring. Apple has finally discovered how to put lipstick on a pig and turn it into an _____!Parlour,
My razr offers me the choice of where I wish to make the preferred storage. Two choices--internal hd or external memory card. There is an additional setting where with one click the program will scan your entire internal (harddrive)storage for music,photos and videos only, and if there are any it will give you the option of storing them internally or externally.
Furthermore, many Android apps giving you the option of placing them on the memory card, certainly handy when you're talking about apps like Google Sky Map or many of the games . NFS was a 100mb download.
I'm no expert, but I believe storing an app on the SD card doesn't equate to a performance loss.
steven75 - Friday, March 16, 2012 - link
Please try using an iOS device before commenting on one and making yourself look dumb.gamoniac - Friday, March 16, 2012 - link
I got an iPad2 for my folks. I like it but it's a deal breaker for myself because it does not have any USB port or SD card slot. Apple should include these; for people who don't want to use them, simply don't. For me, they are a must.Like others have pointed out, other Mac products have SD slots, so what are the excuses? None, it's all about profits. Not all SD cards are born equal.
NCM - Friday, March 16, 2012 - link
Gamoniac writes: "Like others have pointed out, other Mac products have SD slots, so what are the excuses? None, it's all about profits. Not all SD cards are born equal."You seem to be confused: the iPad is not a Mac product. Macs use OS X, but the iPad uses iOS, and iOS by design does not have a user accessible file system. Your imagining motives, base or otherwise, for what some company does is unlikely to result in an argument that's convincing.
Now it might suit your convenience to have a user accessible file system, or some other way to manage extensible storage, but that's not the market that Apple is serving. And the iPad sales results suggest, to say the least, that Apple is not wasting its efforts.
However if that's not what you want, then get a Galaxy Tab or some other product.
chasm22 - Friday, March 16, 2012 - link
Listen steve. I'm sixty years old. I've been around the block. Still, I continue to be amazed by simple-minded statements like yours.I'm assuming you're capable of understanding what a sequence of events are?
Your buddy name99 injected himself into this thread with this paragraph [; "Go buy a fscking playbook or whatever it is you want and stop wasting our time with the same damn complaints we've been hearing since the original iPhone"??? I responded. And somehow, in that sparsely populated portion of your body you use to convey your 'thoughts'(forgive me for taking some liberty with this word)you can only manage to squeel that I need to buy an Apple product or I might look dumb? Sir, can I ask if you possess a physician's recommendation for the use of marijuana and if you do could you please let me know which collective you use? Because there are times when I wish I could go brain dead as you seem to have done.
Or perhaps you worship at the church of Our Ignorance Is Blissful,
yankeeDDL - Saturday, March 17, 2012 - link
Wow. Well said!KitsuneKnight - Friday, March 16, 2012 - link
Having used first an iPod Touch (2nd Gen, IIRC I got it around the time Android was first coming out), then a Galaxy S, and now an iPhone 4S, I have to say I definitely prefer the iOS ecosystem.I like to install random apps to try them out, but apps in Android land seemed to regularly want to puke out random data to the SDcard (and yet, generally not the saves...). Every app, also, had their own idea of the appropriate place to store its arbitrary data on the SDcard... some would just dump it into the root directory, others would put it in Config (IIRC that was the name), others would make a folder with the name of their app... every conceivable place!
This meant that, over time, the SDcard was littered with all sorts of random files belonging to who-knows-what program. Deleting the programs wouldn't clean up the mess they left on the SDcard.
Of course, you also have to worry about moving programs over to the slow-ass SDcard, because the manufacturer cheaped out and only put 2 gigs of internal memory into the thing (but just the variant sold on this network in this region... thanks Samsung)! And SDcards are SLOW, even "fast" ones in comparison to internal storage.
Unless Google manages to enforce some consistency in Android land, I don't think I'll be returning anytime soon. At least I don't have to root my iPhone to be able to make a backup!
UpSpin - Friday, March 16, 2012 - link
If you prefer not having access to a a file system at all (iOS) I don't understand why you bother accessing the file system on Android then? You can use Android just like iOS, just don't open a file explorer, you don't have to. You can open images via the image viewer, music via music player, ...Moving apps to SD-Card should be a thing of the past, of older phones. You also can get an iPhone full, but there there's no option to extend storage as it is on Android, there you have to buy a full new more expensive iPhone.
SD-Cards are slow? How do you notice. As a HTC Desire user I'm forced to put all my apps on the SD-Card and I don't notice any delay.
Backup: You can do a full OS backup on a iPhone, just as you can with Windows or any other mature OS? No! But you can with a rooted Android phone. Without root you can do a backup of your personal data.
parlour - Friday, March 16, 2012 - link
As I said, it’s not an unsolvable problem, but it adds complexity.gorash - Thursday, March 15, 2012 - link
Slow crappy external memory? Yeah, right. MacBooks come with SD card slots so you can't use that excuse. Gotta love how the fanboys justify everything.