05-02-2017 09:45 AM
Welcome to Lenovo Community! And happy to have you again.
As I understand that you have query regarding memory upgrade to DDR4 in your ThinkPad T450
The quick answer would be no as DDR4 RAMs is not backwards compatible with DDR3 motherboards and vice versa. And also the notch has been moved to prevent accidental insertion of the wrong type of memory. Instead of 204 pins, each module features 260 pins in DDR4 Memory.
I hope the above information helped you.
Please feel free to post in Lenovo Community Forums if you have any further queries!
Tap that Kudos button if I helped.
If you find a post helpful and it answers your question, please mark it as an "Accepted Solution"!