Mixing different size ram?

[JackBlack]

Hi, I just bought new ram to replace my old ram because it was discontinued...

My old ram was Corsair Vengeance Pro ddr3 2x4gb for 8gb @2133hz
My new ram is Corsair Vengeance Pro ddr3 2x8gb for 16gb @2133hz

if I wanted to add that extra 8gb of ram, would it be safe? The only difference is the product code because it's 16gb and not 8gb... It might be useless but I would just like to know if that is a possible option that is safe to try and/or use... Thank you

[themctipers]

doable, and might work

[mikat]

It's safe and you can use it  

[NoxiousOdor]

In the past I've seen mismatched ram work but I have also seen it cause problems. It is worth a shot though, the few times when it didn't work for me all I had to do was take out the ram that didn't match and then everything was fine.

[JackBlack]

This is the comment I got from another website, 

It will be safe, no hardware damage will occur, but even if the memory timings are identical the system may be unstable.

Before proceeding, check the motherboard manual, depending on MB, it may not be possible to mix memory this way, or it should be done a certain way.

I have a Maximus VII Hero , I don't know what to look for in the manual