The ever-excellent crew over at iFixit completed their initial teardown of the Early 2015 MacBook yesterday, creating some very nice shots of the Mac’s little logic board in the process. However not stopping there the crew also detached the SSD controller from the board, giving us our best look yet at what we strongly believe to be an Apple-built semi-custom or fully-custom SSD controller.

Images Courtesy iFixit

On the logic board itself, we can see that iFixit’s sample is equipped with Toshiba MLC NAND, 128GB per side, one package per side. However of greater interest is the chip bordered in orange, which based on the fact that it has multiple markings we believe to be the SSD controller, assembled in a Package-On-Package (PoP) fashion. The number we can decode is a part number for a 512MB Hynix LPDDR3 memory module; the other number we cannot decode at this time.

Multiple markings in this fashion is a tell-tale sign of a PoP chip, and having the SSD controller and its DRAM on-package with each other and located right next to the NAND chips makes a ton of sense, especially in such a cramped design. That said, while it means we can’t directly access the SSD die, it also confirms that this is not a strictly off-the-shelf SSD controller since someone had to go through the extra step of PoPing it.

Images Courtesy iFixit

Meanwhile having detected the chip from the logic board, we can see the underside of the chip, which has additional markings. At this time we are unable to decode the part number, 338S00055, though based on the location and PoP design we believe it to be the SSD controller. Otherwise the fact that it doesn’t match any other SSD controller part numbers is yet another clue that Apple had some kind of hand in developing the SSD controller.

Apple in traditional fashion is mum on the whole matter, but we’ll keep digging to see what else we can uncover about this unexpected surprise in their latest laptop.

Source: iFixit

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  • iwod - Thursday, April 16, 2015 - link

    The thing that surprise me is the size of the controller, Compared to CPU+GPU, that thing is huge!
  • liu_d - Thursday, April 16, 2015 - link

    It's likely built on a much larger process node than the CPU/GPU's 14nm. Also, package vs die.
  • Wolfpup - Friday, April 17, 2015 - link

    Oh yeah, good point. Because like iwod, I'm like "why is that thing so freaking huge compared with a dual core broadwell!"
  • Einy0 - Thursday, April 16, 2015 - link

    I would guess an FPGA with an embedded ARM core or two base on the sheer size of the chip.
  • extide - Thursday, April 16, 2015 - link

    Yep, I bet you are spot on.
  • extide - Thursday, April 16, 2015 - link

    On second thought, maybe not. It is apparently a custom ASIC fabbed at TSMC, so not an off the shelf fpga+arm.

    Also another thing that I am wondering about is why the extra elpida DDR3 chip? THere is the 8GB system ram on the top side, the 512MB DDR3 for the SSD on the top of the PoP -- but whats that additional elpida 512MB DDR3 doing? (It's the one in green in this pic)..
  • Penti - Friday, April 17, 2015 - link

    You normally need DRAM for the SSD controllers, 512MB is a common size. It's quite complicated business and it's not something high-end SSD's do in cache/SRAM.
  • Penti - Friday, April 17, 2015 - link

    There's also no access to system RAM.
  • Penti - Friday, April 17, 2015 - link

    Dunno about the Elpida though. But it could be for other embedded cpu's or microcontrollers.
  • extide - Friday, April 17, 2015 - link

    The SSD controller has it's own separate DRAM. The elpida ram is not used for the SSD controller.

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