This 8GB RAM is 100% compatible with the Apple iMac18,3. The RAM is installed as standard with 2 x 4GB of memory. When configuring through Apple, a higher capacity RAM can also be selected, but the additional cost is significant. In contrast, upgrading the RAM is affordable and easy to do. The existing memory does not need to be replaced. There are four memory slots, two of which are free.

The most common memory configurations chosen by customers for the iMac18,3 systems are:

• 24GB RAM with 2 x 4GB + 2 x 8GB
• 40GB RAM with 2 x 4GB + 2 x 16GB

Model and maximum RAM configuration in Apple iMac18,3 models:

• iMac Core i5 3.4 27-inch (5K, Mid-2017): 64GB (4 x 16GB)
• iMac Core i5 3.5 27-inch (5K, Mid-2017): 64GB (4 x 16GB)
• iMac Core i5 3.8 27-inch (5K, Mid-2017): 64GB (4 x 16GB)
• iMac Core i7 4.2 27-inch (5K, Mid-2017): 64GB (4 x 16GB)
• iMac 18,3 - overRAMing: 128GB (4 x 32GB).