Additional RAM configuration advice

[MrBedo]

I'm looking to upgrade from 8gb to 16gb of Corsair Vengance RAM. I currently have two sticks of 4gb and it was my intention to add an additional two sticks.

Having had a look, I can see that the CPU fan is partially blocking one of the RAM slots, thus limiting my upgrade to one additional stick.

Would there be any adverse effect if I added a single 8gb stick instead of matching the existing config and adding an additional two sticks of 4gb?

Mobo is an ASUS P8P67 PRO.

Thanks in advance for any advice.

[PeteG@Scan]

The boards are designed to be speed optimized when running in a dual channel set up. If you have an odd number of sticks you'll loose memory bandwidth as the board reverts to single channel performance.