4.8ghz is a hefty overclock. Unless you have invested in some custom watercooling, or at the very least an AIO dual 120mm rad, I don't even recommend going that high, especially at that voltage. I run my 3770K at 4.2ghz with a single 120mm rad with dual Corsiar fans and although 4.5ghz will run just fine, I see the value of that extra 300mzh diminish when my cpu is hitting 85C. Thats me though. By all means run your rig on the ragged edge, its fun and a challenge and if you have the dough to replace parts, I say go for it. The 4 series chips will still run hot overclocked, but they seem to overclock much better at lower voltages. All that said, I still say wait and at least see what overclocking the new chips is like.