iMac (21.5-inch, Late 2012) - Technical Specifications
How much Unified memory does your Apple silicon Mac need?
Apple – Support – Technische Daten (DE)
iMac (Retina 5K, 27", 2020) - Technische Daten (DE)
GitHub - upekkha/AppleHardwareTest: Apple Hardware Test Download Links
Reparieren oder Wiederherstellen eines Intel-basierten Mac mit Apple Configurator - Apple Support (DE)