Corsair Vengeance 16GB (2x8GB) DDR3 1866MHz compatibility with P7P55D LE motherboard

You are perfectly fine. But just to save you some money, there's no need to buy that much ram.

8GB is enough to simultaneously run battlefield 3, photoshop, AND 30 tabs in chrome.

Unless you're working on heavy video, audio, or image editing, you pretty much don't need 16gb.