Hi [NAME] welcome to this free user-to-user Alienware laptop discussion forum.   Dell (10/24/2018) support for Alienware m15 (R1) says it has been tested for 32GB installation of DDR4-2660.   The more recent Crucial System Advisor database says the Alienware m15 will accept 32GB of DDR4-3200. Alienware Alienware m15 | Memory RAM & SSD Upgrades | Crucial.com.  
Hi,  I am using a 2019 Alienware m15 R1 with 8GB of ram and i7 9th gen CPU. I wanted to upgrade my ram speed from 2666 MHz to 3200 MHz. Will my motherboard support this 3200 MHz upgrade? thanks 
m15 R1, upgrading ram speed to 3200 MHz?