Install memory in an iMac - Apple サポート (日本)For optimal memory performance, DIMMs should be the same capacity, speed, and vendor. Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria: PC4-21333 Unbuffered Nonparity 260-pin 2666MHz DDR4 SDRAM If you have mixed capacity DIMMs, see the install memory section for installation recommendations. iMac (Retina 5K, 27-inch, 2019) Get memory specifications for iMac (R
