Editing PCI Express (section)

==== Mini-SATA (mSATA) variant <span class="anchor" id="MSATA"></span> ====
[[File:Intel 525 mSATA SSD.jpg|thumb|upright|An Intel mSATA SSD]]
Despite sharing the Mini PCI Express form factor, an [[mSATA]] slot is not necessarily electrically compatible with Mini PCI Express. For this reason, only certain notebooks are compatible with mSATA drives. Most compatible systems are based on Intel's Sandy Bridge processor architecture, using the Huron River platform. Notebooks such as Lenovo's ThinkPad T, W and X series, released in March–April 2011, have support for an mSATA SSD card in their [[Wireless WAN|WWAN]] card slot. The ThinkPad Edge E220s/E420s, and the Lenovo IdeaPad Y460/Y560/Y570/Y580 also support mSATA.<ref name="5xxpo" /> On the contrary, the L-series among others can only support M.2 cards using the PCIe standard in the WWAN slot.

Some notebooks (notably the [[Asus Eee PC]], the [[Apple Inc.|Apple]] [[MacBook Air]], and the Dell mini9 and mini10) use a variant of the PCI Express Mini Card as an [[solid-state drive|SSD]]. This variant uses the reserved and several non-reserved pins to implement SATA and IDE interface passthrough, keeping only USB, ground lines, and sometimes the core PCIe x1 bus intact.<ref name="EeePC" /> This makes the "miniPCIe" flash and solid-state drives sold for netbooks largely incompatible with true PCI Express Mini implementations.

Also, the typical Asus miniPCIe SSD is 71&nbsp;mm long, causing the Dell 51&nbsp;mm model to often be (incorrectly) referred to as half length. A true 51&nbsp;mm Mini PCIe SSD was announced in 2009, with two stacked PCB layers that allow for higher storage capacity. The announced design preserves the PCIe interface, making it compatible with the standard mini PCIe slot. No working product has yet been developed.

Intel has numerous desktop boards with the PCIe x1 Mini-Card slot that typically do not support mSATA SSD. A list of desktop boards that natively support mSATA in the PCIe x1 Mini-Card slot (typically multiplexed with a SATA port) is provided on the Intel Support site.<ref name="xpI66" />