SanDisk A110 PCIe SSD: Armed With The New M.2 Edge Connector

More On M.2 And SanDisk's Fancy PCIe Adapter Card

In case the previous page didn't clarify M.2 for you, don't sweat it. I created the diagram above to (hopefully) inject some clarity, since this entire discussion gets a little confusing. In reality, M.2 refers to the connector manufactured by companies like Kyocera and Tyco. Again, solid-state drives employing the M.2 connector are 22 mm wide, better accommodating NAND packages and processors down the length of the PCB. That length can be 42, 60, 80, and 110 mm. So, a M.2 2260 is 22 mm wide and 60 mm long. Get it?

That's the obvious, physical stuff. There's also plenty to digest when it comes to the technology on an M.2-based SSD. Use a SATA controller, and you end up with something similar to an mSATA-equipped drive (so long as the M.2 slot is wired up to a corresponding SATA port on your motherboard; otherwise, there needs to be a PCIe-to-SATA bridge chip in play).

Then you have native PCI Express controllers like the one on SanDisk's A110. It boasts Marvell's 9183, which, communicates across those two lanes of second-gen PCI Express. There will be native NVMe-based controllers that attach via PCIe and work with the upcoming host interface. For now, though, the A110 is limited to AHCI. This is the case for every current and most upcoming M.2 PCIe-based drives.

Still following along? Let's pile on some more. SSDs with M.2 connectors can use one, two, or as many as four PCI Express lanes. SanDisk's sample employs two PCIe 2.0 lanes, which should become fairly standard, we understand.

We probably don't need to tell you that the test platforms already in our lab don't yet support M.2. One motherboard vendor is starting to show off LGA 1150-based platforms with M.2 linked to one PCIe lane, but we'd prefer to use our main SSD testing setup. Not only would stepping over to a new board yield different results, but limiting the A110 to one lane would inhibit its performance.

That's why we need this bad boy:

This is SanDisk's PCIe x4 to M.2 adapter. Without a proper slot to accommodate the A110, we need this full-height card to test any SSD with an M.2 connector. These are for testing and development, and come with a variety of arcane jumpers, along with a USB port for debugging. The PCIe-based M.2 can be powered through either the PCIe bus or the four pin Molex. That'll come in handy for power consumption testing.

With just two different PCIe M.2 form factors, the adapter doesn't need to support every length. Installing the M.2-based SSD is easy; plug it in the connector and then secure it with a cylindrical barrel.