I bought an intel i5 4670K, Asus Z87-A motherboard and Corsair H80i CPU cooler a few days ago. I have been trying to find a stable overclock ever since day one. Stress tests like AIDA64 and Intel utility show that my system is stable. Idle temperatures are around 35C for both CPU and GPU (Asus GTX 670). At load, my CPU gets to about 60C and my GPU gets to around 70C. Stress tests show 0% throttling. I eventually got very frustrated and decided to bring everything back to stock settings. But all my games continue to crash 10-20 minutes into gaming. Sometimes the crashes result in a full system restart.