Apple’s Unconventional New MacBook Air SSD

Apple updated the ultra-slim don’t-call-it-a-netbook MacBook Air this week. Along with a wimpy out-of-date CPU, the new Air features all-SSD storage of an entirely new and apparently proprietary type. Let’s take a look and see what we can see.

Just The Facts

You might want to read my piece about Unconventional SSDs: PCI Express Mini Card (Mini PCI-E) or the updated information in Toshiba Offers “Blade” SSDs (Like Apple’s MacBook Air)

The MacBook Air isn’t supposed to be upgradeable, and Apple went so far as to use a special 5-point Torx-ish safety screw to keep us out. As revealed by iFixit, just about everything inside is soldered in except for the Wi-Fi and SSD cards. Apple, shockingly, included an inside shot of the 13″ Air on their official Design page, showing that both machines use the same SSD connector.

Is this new form factor called a “blade SSD”?

• The Air uses a new type of connector that looks a lot like a Mini PCI-Express slot but definitely isn’t.
  • The connector is exactly the same width as the USB shield: That’s about 7 mm, not the 24 mm of a Mini PCIe slot.
  • This connector is used for both the AirPort (Wi-Fi) board and the SSD, so it’s not some kind of shrunken SATA port.
  • The SSD has contacts on only the “bottom” side with what looks like a ground plate on the “top”, while the AirPort seems to have contacts on both sides (or at least on “top”).
  • The connector is split with six pins on one card edge and 12 on the other. A one-sided version thus has 18 pins (plus ground) while a two-sided variant has 36 pins. For comparison, Mini PCIe is a two-sided card edge with 8 pins and then 18 pins, for a total of 52 pins.
• System Profiler reports that the SSD and AirPort connect to the NVidia MCP89 chipset in different ways:
  • The SSD is a SATA device on the AHCI lines. While it’s possible that Apple could have designed an internal SATA controller and be presenting it on a PCIe lane, it’s much more likely that it’s really using SATA over the new connector described above. Since SATA needs just 5 or 6 pins plus ground (4x data and 3.3 volts and 5 volts of power), there are plenty of connectors for it.
  • The AirPort (802.11n Wi-Fi) card, on the other hand, appears to be using a PCI Express lane. Since PCI Express also needs just 6 to 8 pins, this fit, too.
• The cards are much smaller than conventional Mini-PCIe cards as well:
  • The SSD is 24×108.9 mm, much smaller than the 30×51 mm typical of Mini-PCIe SSDs. This compact size makes the Toshiba NAND chips appear to be giants, but they’re really the same chips used on other SSDs.
  • The AirPort card is really compact at about 22×30 mm.

It appears that Apple (or their supplier) has developed this new form factor to be even thinner and narrower than the already-small PCI Express Mini Card format. One wonders if other vendors will adopt this new smaller “Air Card” format as well.

Stephen’s Stance

If the MacBook Air had used a PCI Express-based SSD like the Fusion-IO or OCZ models, it really would have been a revolutionary move. But booting a computer from a device like this would have been challenging, requiring revisions to the EFI firmware, drivers, and Mac OS X itself. Therefore, it is not surprising to see a SATA connection used instead. So no, Robin, this isn’t the end of SATA (yet).

Yup, it’s SATA. More information is available in my article, Toshiba Offers “Blade” SSDs (Like Apple’s MacBook Air)

Some will undoubtedly complain about Apple’s proprietary format, but this is neither a new development nor a particularly damning one. Most modern Macs, including the MacBook, MacBook Pro, and Mac Mini, already use proprietary AirPort daughter cards and no one howled in protest when they switched from standard PCI Express Mini Cards. Having the storage on the same type of connector is good from a bill of materials standpoint, saving Apple a few dollars. And this is not an upgradeable machine. Moaning about the low-spec Core 2 Duo CPU and soldered-on 2 GB of RAM is much more sensible than whining about a proprietary SSD.

Images from Apple, Inc. and iFixit.com