Are these two sticks compatible and why is disk speed at 100%?

[stekenney]

Need help making sure the new stick of ram will work in Dual channel mode with the other.

Are these two Ram sticks compatible/Disk Speed 100%?

I just completed my first build and my MOBO came with the Gskill Ram. The problem is it only came as a single stick and since I bought it in America and live in England I can't get a matching stick here.
Will these two work together?

Crucial Ballistix Elite 4GB (1 x 4GB) DDR3-1866 Memory

G.Skill Ripjaws X Series 4GB (1 x 4GB) DDR3-1866 Memory

http://www.amazon.co.uk/dp/B006TB2TT4/?tag=pcp0f-21

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231720

Current Build; http://uk.pcpartpicker.com/p/2KHJX

Also, my new build started to run slow after an hour or so. I opened task manager and my Memory is almost at 100% (I am getting another 4gb anyway) but why is Disk speed up to 100%? Is that memory related?

 

[sora]

They should work together, don't see why it wouldn't.

A memory leak or horribly coded keylogger could be causing your CPU usage to skyrocket up to 100%. You might wanna run Malwarebytes and do a system scan.