Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
What frequency would one have to run an E8400 to unbottleneck a 4870. I have heard 3.6 and 3.8 GHz thrown around but am unsure as to how reliable those numbers are considering I haven't a clue myself.
core 2 duo at 2.4 is more then enough already as demonstrated by several review sites by running real life gaming tests. Going up to 3.0 ghz core 2 will give you a dozen or two extra fps depending on the game but any higher clocks then that will only start showing even more diminishing returns.