I have an imac core i5 3.2 27 inch 5k late 2015 model id imac 17.1 emc no 2834.I have just bought 2 by 8gb memory for it which will go along side of 2 by 4gb memory. Can I put these in as it is or do they have to go a certain way round in the slots Thanks.
Thank you for your question. First of all, thank you for picking Crucial for your upgrade.
You will be able to add the memory to the empty slots and it will work next to your existing memory modules. I have found the installation instructions for that model on the Apple website here: https://support.apple.com/en-gb/HT201191
If you do have any questions, please don't hesitate to ask. Enjoy your upgrade!