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Comment by cdr | Hacker News Reader

> M.2

My impression was that M.2 is going out of style, at least for desktop - the primary form factor for the Intel 750 etc is an actual PCIe card. The alternative connector if you want a 2.5" drive form factor is U.2 (SFF-8639).

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The Intel 750 is officially speaking a consumer product, but it's pretty out there. M.2 is far more popular and is doing a pretty good job of supplanting mSATA and effectively prevented SATA Express from being adopted. U.2 is brand new and is only going to show up on the most expensive consumer products, but M.2 can be found on a lot of motherboards under $100.

You're right, it looks like most of the Skylake launch boards in Anandtech's review are M.2. Somewhat disappointing. I still suspect M.2 is obsolete in the long run, but seemingly not for this generation of Skylake.

There are at least a couple boards I see with a dedicated PCIE 3.0 x4 slot and U.2 support, but they're the highest end and I'm sure not cheap.

You can connect a 2.5" U.2 drive (Intel 750) to M.2, but it's obviously going to reduce performance to M.2 speeds.

M.2 supports the same performance as U.2. Both connectors allow for up to 4 lanes of PCIe. Some lower-cost implementations of M.2 only provide 2 lanes, and it also can provide SATA signals instead of PCIe, but with Intel's desktop chipsets finally getting a bandwidth upgrade everybody is going to be implementing M.2 with four lanes going forward.

Ah, I guess I'm used to the Haswell DMI bus speed still, which severely limited M.2 speed even if it was 3.0 and 4 lanes. I guess that's probably not the case with Skylake.

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