No, these two RAM types cannot be used together.
No, these two RAM types cannot be used together.
Sure, I can help with that. Your current setup has 8GB of 2133MHz single-rank RAM, and you're considering adding another 8GB stick. The market offers 8GB dual-rank CL15 RAM, but since your existing RAM is single-rank, combining it with dual-rank sticks isn't straightforward. You'd need to ensure compatibility and possibly use a different configuration.
I'm using an 8 gig stick which is dual rank, plus two 4 gig sticks that are single rank. I've never had any problems with this setup over the past two years. (Slots 2-8 gig stick, slots 3 and 4 have 4 gig sticks) You might run into XMP issues, though—possibly or more likely. That's probably because of me. But my RAM works at 2666 regardless.
I see a comparable setup on my laptop too—no issues there. It has one 2400 single-rank RAM module and one 2133 dual-rank module, which I got from an older machine. Even with this mismatched configuration, it still performs better than the single stick was.