Question Overclocking failure

[Rikvdb22]

Hello, I recently tried to overlock my cpu on an older PC, wich had the following specs:
Operating System: Windows 10 Home 64-bit
Mobo: Z170m-Plus
Ram: VENGEANCE® LPX 16GB (2 x 8GB) DDR4 DRAM 3200MHz C16 Memory Kit - Black
Processor: Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz (4 Cores)
Graphics Card: NVIDIA GeForce GTX 750 Ti
PSU: Corsair VX450W
Storage: 1 SSD with OS and 3 Hard disks

First of all i want to say that this is my first time trying to OC.
So have my CPU running at 4,6 Hz with a voltage of 1,35V and did a stress test with aida 64 Extreme for about 19 hours and everything seemed fine. My CPU temp didnt go higher than 70 degrees. But i only stressed my CPU, Fpu , cache and Ram. When i try to play csgo my game crashes after 30-45 mins. So i did the stress test again but this time with the gpu stress test also enabled and after 4-5 mins it detects a hardware failure. I didn't OC my GPU at all and i dont know if i should restart from the beginning all over again so if anyone would be able to help me it would be highly apreciated.

 

[kerberos_20]

if you touched FSB (BCLK) clock, than that hardware failure could be comming from pci express

 

[zx128k]

Repair CS:GO's install first but you do appear to be unstable. It could be that your PCIe bus is unstable, system agent voltage feeds the intergated PCIe-controller (CPU VCCSA https://www.hardwaresecrets.com/understanding-all-voltage-configurations-from-the-motherboard/4/ ). Never overclock the PCIe buss speed, too many things break because of it. Also the Corsair VX450W could be a load of crap and/or you are pulling too much from the PSU. https://linustechtips.com/main/topic/1116640-psu-tier-list-40/