Combining Ram?

you haven't linked to a specific piece of crucial ram so don't know, but as long as it's basically the same as the mushkin then no reason why not.

Doesn't look like the crucial is any cheaper so why not get the same mushkin as you have then you are 100% sure.

Heres the ram sry http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Those are two different voltages.

so it's not gonna work...

What would happen if I combined them?

Your computer will starting nagging you about how it doesn't feel good, and something is wrong.
If you keep it in there to long you are going to kill it...

Two different voltages isn't a good thing.

Just buy the same brand/type and you'll be fine.

Thanks then:}