@Xipper
Something doesn't sound quite right with your OC based on my (very limited) experience with the same board.
I have the same board and CPU, XMP enabled on the RAM (4x 4GB Corsair Vengeance Low profile) and also using a H100 and I'm hitting just under 16000 in Geekbench with a 4.2Ghz OC compared to your 4.8Ghz.
Haven't messed with voltages, ram timings or anything like that, just enabled the XMP and set the multiplier to 42.
Only thing I can think is your HD4000 graphics are the cause of the lower geekbench rating. (And possibly because I have a dedicated graphics card).
Interestingly I did some testing on the RAM performance boost option (the option that lets you set Normal, Turbo or Extreme) and oddly got the best geekbench score with it set to Normal. (Turbo is the default setting). Seemed a bit counter intuitive to me!
Can I ask why you are switching to a H80 from a H100? In addition, have you checked your temps with hardware monitor?
I thought (from what I've read online) that the 3770K starts to get a bit toasty once you reach 4.5Ghz.