Used Corsair Vengeance 32GB (2x16GB) DDR4 Ram PC4-19200
Apple iMac 21″ 4k Mid 2017 – Maximum ram 32GB (2x16GB) – RAM is NOT user accessible*
Apple iMac 27″ 5k Mid 2017 – Maximum ram 64GB (4x16GB) – RAM is User accessible
Will also fit various PC systems meeting the system requirements of the ram.
16GB per module
DDR4 2400mhz PC4-19200
*Fitting is recommended only to be carried out by a professional on the 21″ iMac as it involves a full teardown. Because of the labour involved I also generally only recommend it whilst you’re also having other work like an SSD fitted so the costs are shared.