Possible to use slower DDR3 memory on late 2015 27" iMac?

[lsquare]

I can get Crucial DDR3L PC3-12800/1600 for a pretty good price. This particular model of RAM worked on the 2014 version of the 27" Retina iMac so I'm kind of hoping to avoid having to pick up more expensive DDR3 1867mhz memory.

 

[Blatzman]

I put 32gb of pc3-12800 in my late 2015 and it worked fine. I did remove the 8gb that came with it so I didn't have mixed speeds.

 

[ucfgrad93]

I don't see any problem doing that.

 

[iemcj]

It's not going to make a noticeable difference in anything. Might make working with a giant 4k video file take an extra quarter second here and there but ram speed has been shown to make very little difference the past few years.