Should I upgrade my RAM with 2400 stick or 2666? Manual said 2400 but existing memory is 2666

[shiazen]

Hello. This is my first time upgrading RAM and I have no idea which is right. I have a 15-db1038au HP notebook and it said it supports RAM running at 2400Mhz, but I checked using cmd and found out the existing RAM module is this: https://www.samsung.com/semiconductor/dram/module/M471A5244CB0-CTD/ (it came with the laptop)

People said it's best to buy a matching stick so I bought one with exact same module number online. I haven't installed it because when I checked through cpu-z the existing memory only run at 2400MHz (1197,6Mhz DRAM frequency) which is what the manual stated. So should I use the matching stick i just bought that has 2666Mhz frequency or should I look another one with 2400Mhz frequency? What difference does it make? Thank you.

[Paul_Tikkanen · Accepted solution]

Hi:

You should use the matching stick you bought. 

It will automatically downclock to 2400 MHz, which is the fastest speed the Ryzen processor can run the memory at.

Here is the link to the service manual where you can find the memory removal and replacement procedure...

http://h10032.www1.hp.com/ctg/Manual/c06245081