苹果2017款2019款 5 K imac-一体机指定内存 SKhynix 32GB2Rx8PC4-2666V-SE1-11 KOREA HMAA4GS6AJR8N-VK NA AC 1952 SKhynix 32GB2x8PC4-2666V-SE1-11 KOREA HMAA4GS6AJR8N-VK NA AC 1952 32G*2=64GB双通道不降频