Any help would be great trying to get my head around the new bios loads more settings to play with any decent guides
There's not much to learn over the 2500K to be honest. The only new thing is the introduction of the input voltage due to the FIVR (Fully Integrated Voltage Regulator(s)) on the CPU which Intel thought was a good idea... and the introduction of the cache multiplier/voltage. I'd say you should start at 1.3 volts and 45x on the CPU multi, leave the cache at stock as it is a pain to clock and does not gain you very much at all. See if it is stable, just like you would with your Sandy chip, and then adjust it accordingly. 4.5 at 1.3v shouldn't be too much to ask, but some chips can't do it. Any ideas what the previous owner had it running at? Oh, also, do NOT check it with the latest Prime that has AVX included. It will add 20c+ to your temps. Test it with Prime 26.7 or something near to that.
As per what Brendan has said, no games use AVX neither do 90% of professional applications so it's a pointless exercise running the version of Prime with it included.
this is a fairly comprehensive guide. But as MadDutchDude says, not much is different from Sandy/Ivy.
I did a bit of research when I first got my Haswell refresh 4690k. I use a z97 board but I don't think there's all that much difference. These are the "limits" I worked from. CPU input voltage: max 1.9v. My I5 is happy at 4.5GHz with a input voltage of 1.85v, but needs 1.89v for a stable 4.6GHz. CPU Vcore: max 1.3v for safe 24/7. My I5 needs 1.29v for a stable 4.6GHz. Don't bother with overclocking the cache until you've found your optimum core overclock, and even then it's not really worth the bother. I think I've got my cache up to 42x at 1.15v but tbh it doesn't make any noticeable difference.
