DDR3L @ 1.6ghz vs DDR4 @ 3 ghz

[Blasqen]

Hi guys, last year I upgraded my laptop (hp zbook 15g2) with an extra 8 GB of ddr3l ram. The speed of this memory chip is 1.6 ghz.

Now, currently I am building a dekstop (I7 8700 + gtx1080ti) and I was wondering if I can reuse that strip of ram (and buy an additional one for a total of 16 GB) or buy 2 brand new DDR4 8 GB memory modules at 3 GHZ each?

I am reading mixed opinions on how much ram speed matters. I will use the new PC for gaming, streaming, programming and machine learning.

 

[gingerrankin]

With i7-8700 you can only use DDR4.

A minimum speed of 2666 is recommended. In Intel CPUs, an increase in memory speed has 3200 influence very little (unlike in Ryzen)