Alienware 17 R4, i7-7820hk, GTX 1080 overclock and undervolt help needed.

I searched both reddit and NBR forum's but most of the guides are for skylake chips, can someone help me with achieving good overclocking and stable undervolt.
I tried OC Lvl 1 in BIOS with undervolt of -100mV but while playing witcher 3 the CPU max temp reached 100 C
When using stock speeds and undervolting -150 mV the max temps while playing Witcher were 86 C.

 

You could opt for a repaste or remove/disable unneeded background apps and services.

 

You must contact Dell support to change your rad for Sumon rad...

 

Wut?

Way to hot, your overheating and hitting thermal throttling no doubt. Contact support and tell them you need a repaste / replacement heatsink. How were the core differentials? I presume they are probably terrible.

Overclocking is always going to generate more heat but with a proper paste job most are OCing to 4.1-4.3 and not seeing 90c.

 

The core differentials are not that bad around ~3-4 C between cores.

 

Can DELL India do a repaste job properly?

 

@iunlock like repasting and quality checking, never. Do you have the top end model with 1 TB SSD?
Follow @iunlock guide to repaste and repad. Dell are rejecting more cases because of parts issue, I guess,

 

Repaste + get a laptop cooling pad.

 

A weapon to surpass metal gear