Editing PCI Express (section)

=== PCI Express Mini Card <span class="anchor" id="MINI-CARD"></span> ===
<!-- [[PCI Express Mini Card]], [[Mini PCI Express]], [[Mini PCIe]], [[Mini PCI-E]], and [[M-PCIe]] redirect here. -->
[[File:Intel WM3945ABG MOW2 and its connector 20070216.jpg|thumb|A [[WLAN]] PCI Express Mini Card and its connector]]
[[File:MiniPCI and MiniPCI Express cards.jpg|thumb|MiniPCI and MiniPCI Express cards in comparison]]

'''PCI Express Mini Card''' (also known as '''Mini PCI Express''', '''Mini PCIe''', '''Mini PCI-E''', '''mPCIe''', and '''PEM'''), based on PCI Express, is a replacement for the [[Mini PCI]] form factor. It is developed by the [[PCI-SIG]]. The host device supports both PCI Express and [[USB]]&nbsp;2.0 connectivity, and each card may use either standard. Most laptop computers built after 2005 use PCI Express for expansion cards; however, {{as of|2015|lc=yes}}, many vendors are moving toward using the newer [[M.2]] form factor for this purpose.<ref>{{cite web | url=https://arstechnica.com/gadgets/2015/02/understanding-m-2-the-interface-that-will-speed-up-your-next-ssd/ | title=Understanding M.2, the interface that will speed up your next SSD | date=8 February 2015 }}</ref>

Due to different dimensions, PCI Express Mini Cards are not physically compatible with standard full-size PCI Express slots; however, passive adapters exist that let them be used in full-size slots.<ref name="DmwJz" /> 

==== Physical dimensions ====
Dimensions of PCI Express Mini Cards are 30&nbsp;mm × 50.95&nbsp;mm (width&nbsp;× length) for a Full Mini Card. There is a 52-pin [[edge connector]], consisting of two staggered rows on a 0.8&nbsp;mm pitch. Each row has eight contacts, a gap equivalent to four contacts, then a further 18 contacts. [[Printed circuit board|Boards]] have a thickness of 1.0&nbsp;mm, excluding the components. A "Half Mini Card" (sometimes abbreviated as HMC) is also specified, having approximately half the physical length of 26.8&nbsp;mm. There are also half size mini PCIe cards that are 30 x 31.90 mm which is about half the length of a full size mini PCIe card.<ref>{{cite book | url=https://books.google.com/books?id=otfPEAAAQBAJ&dq=pci+express+micro&pg=PT628 | isbn=978-0-13-816625-0 | title=IT Essentials Companion Guide v8 | date=9 July 2023 | publisher=Cisco Press }}</ref><ref>{{cite book | url=https://google.com.pa/books/edition/Mobile_Computing_Deployment_and_Manageme/rP5gBgAAQBAJ?hl=en&gbpv=1&dq=mini+pcie+full+size+half+size&pg=PA491&printsec=frontcover | isbn=978-1-118-82461-0 | title=Mobile Computing Deployment and Management: Real World Skills for CompTIA Mobility+ Certification and Beyond | date=24 February 2015 | publisher=John Wiley & Sons }}</ref> 

==== Electrical interface ====
PCI Express Mini Card edge connectors provide multiple connections and buses:
* PCI Express x1 (with SMBus)
* USB&nbsp;2.0
* Wires to diagnostics LEDs for wireless network (i.e., [[Wi-Fi]]) status on computer's chassis
* [[Subscriber Identity Module|SIM]] card for [[GSM]] and [[WCDMA]] applications (UIM signals on spec.)
* Future extension for another PCIe lane
* 1.5&nbsp;V and 3.3&nbsp;V power

==== 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" />