Can I mix Ripjaws Series with Ripjaws X Series?

[Talonos]

I have a GIGABYTE GA-X79-UP4, supporting 8 sticks of memory. When I built my computer four years ago, I got a 4x2 GB Ripjaws kit (https://www.newegg.com/Product/Product.aspx?Item=N82E16820231325)

I now want to upgrade my memory by using the four empty slots. I'm thinking of buying the 4x4 GB ripjaws X kit: (https://www.newegg.com/Product/Product.aspx?Item=N82E16820231429 )

The type, speed, timing, CAS latency, and voltage are all the same. But the size (2 GB vs 4 GB) and the series (Ripjaws vs. Ripjaws X) differ. Will these two memory kits mix?

If not, can I just buy another copy of the 4 module ripjaws kit? Mixing two identical kits should be safe, right?

 

[xJoseph]

not sure if the RAM is going to work fine with the mobo or not, since 2x4 gb kit is running in dual-channel, but the 4x4 gb kit is going to run in quad channel.
Similar to using 2x4gb dual channel and adding a single 8 gb stick which is a single channel.

 

[Talonos]

Good Catch!