Technical Information • PCZ-NVM • CPU Expansion Side Card
M.2 Module Fixation (Picture Similar)
M.2 Connectors
The PCZ-NVM is equipped with two M.2
module host connectors. Mechanical details and pin-out
configurations are described by the PCI-SIG 'PCI Express M.2 Specification'. The M.2 pin-out complies
with the 'Socket 3 M SSD Drive', with module dimensions from 'Type 2242 to 2280', either height
option 'S2, D2, S3, D3, D5'.
Both M-key coded connectors are suitable for PCIe® (NVMe) SSD modules. The M1 connector
provides a PCIe® Gen3 x4 link, derived from the HSE1 mezzanine interface, while the M2 connector
is PCIe® Gen3 x2 configured, routed via HSE2. Both M.2 sockets can be used together with PCIe® x4
based M.2 modules, but only the upper socket M1 delivers the maximum data transfer rate of
4x8Gbps, while the lower socket has its bandwidth limit at 2x8Gbps. The M1 connector can be used
also for a legacy SATA type SSD - the PC7-FESTIVAL carrier card CPU detects the type of SSD and
switches the particular PCIe® lane to SATA mode.
M.2 NVMe and M.2 PCIe® x4 are often used as synonyms. However, NVMe (NVM Express™ -
non-volatile memory attached through the PCI Express
®
bus) is both an interface and also a command
set or software protocol. Any recent operating system should incorporate NVMe drivers. In addition,
the UEFI firmware (aka BIOS) should be verified in order to be able to boot from an NVMe device. This
is true for EKF CPU cards such as the PC7-FESTIVAL.
After insertion, an M.2 module must be locked manually by a screw, in order to withstand shock and
vibration.
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