| Feature | M.2 Rev 3.0 (Ver 1.0) | | M.2 Rev 5.0 (Draft) | | :--- | :--- | :--- | :--- | | Bit Rate | 8 GT/s | 16 GT/s | 32 GT/s | | Max x4 Bandwidth | ~3.94 GB/s | ~7.88 GB/s | ~15.76 GB/s | | Reference Clock | 100 MHz HCSL | 100 MHz with Spread Spectrum | 100 MHz + sideband | | Connector Rating | 50 mating cycles | 50 mating cycles (same) | 124-pin proposal | | Thermal Throttling | Optional | Mandatory (Opal standard) | Enhanced |

Compatible with both socket types, though often limited to x2 speeds. Power Management and Thermal Limits

The PCI Express M.2 Specification Revision 4.0 Version 1.0 remains a foundational document for any professional involved in high-performance hardware design or system integration.