Micron x Ramcity 16GB (1x 16GB) DDR4-2666 PC4-21300 1.2V DR x8 260-pin SODIMM RAM Module Model_Mac_Book_Pro_5_5 MT/s and MHz are used

MT/s and MHz are used interchangeably

CT32G4RFD4266 Capacity 32GB (1x 32GB) Brand Crucial Speed DDR4-2666 - 2666MT/s - PC4-21300 Voltage 1

x8 configuration RAM module from Kingston is for use in DDR3 compatible systems and operates at 1333 MT/s with an overall transfer rate of PC3-10600

This RAM module runs at 266MHz per second

2xCT4G4WFS8266 Capacity 8GB (2x 4GB) Brand Crucial Speed DDR4-2666 - 2666MT/s - PC4-21300 Voltage 1

Micron x Ramcity 16GB (1x 16GB) DDR4-2666 PC4-21300 1.2V DR x8 260-pin SODIMM RAM Module Model_Mac_Book_Pro_5_5 MT/s and MHz are usedCurrent Market Overview In December 2025 Micron announced they are discontinuing the Crucial brand. Crucial was the retail arm of Micron Technology. Effectively they were putting Crucial stickers on Micron modules, Crucial never actually made RAM. Micron has also issued an End Of Life (EOL) on all their DDR4 modules. Samsung and Hynix have also announced the same EOL on DDR4 RAM. This has left the market in a difficult situation with wide spread chip