Your PSU is average at best and not really suitable for overclocking; http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html.
I know, last night I was looking at better psu's and am gonna get this one today with an MIR
Thermaltake Toughpower TPD-0750M - SLI / CrossFire Ready 80 PLUS Gold Certification and Semi Modular Cables Black Active PFC Power Supply Intel Haswell Ready (PS-TPD-0750MPCGUS-1)