Overclocking to 4ghz a cpu lifespan

[camdenpaul]

Hey all, I wondering when you overclock a 3.06ghz i7 950 cpu to 4ghz how much of the lifespan is reduce on the cpu? also can someone here tell me if these bios settings are correct to get 4ghz that someone gave me, BCLK 200, Multi 20, dram freq 1600, pcie freq 101, load line calibration enabled or level 2, cpu vcore 1.3v or 1.325v, dram freq 1.65v and spread spectrums disabled, but i look in the bios and cant find spread spectrums anywhere, all i got is Isochronous support and virtualization technology is it one of them i gotta disable? my rig is 1000w psu, antec 902, constair a70 cooler, gigabyte ga-58-usb3 motherboard, memory Corsair XMS3 6GB (3x2GB) DDR3 PC3-12800C9 1600MHz Triple Channel, x 2 480 geforce cards

 

[camdenpaul]

I need to Overclock that chip really as the standard stock settings when using sli with x 2 480 cards i see hardly any different in framerates in fact its the same as if i was using one card at stock settings, also i got told never to use easytune overclocking software, is it really that bad? but thanks for confirming them settings are correct with the bios as i was a little nervous about it cos i dont want the pc to blow up or something lol