Will 4 pin work in 8 pin?

[siebevelez01]

Yesterday, I built myself a new computer (first time). But when I finished, I noticed that I couldn't connect my 8 pin to power the CPU, because the cable was not long enough. So, I orderer an extension cable which will arrive in like 4 days. So, i was wondering, if I could put my 4 pin in there which, weirdly, is long enough. I actually already did it and the PC did boot, but how far can I go with this 4 pin.
Specs:

i7-6700k
MSI R9 390
16gb DDR4 RAM
Z170a SLI PLUS

 

[EndlessZone123]

As long as your CPU isn't very power hungry. It should be usable but don't stress it. Go to power options in control panel and press the one your using. Then go to advanced and find CPU management or something. Set the max to like 75% and you can change it after

 

[RCFProd]

As long as your CPU isn't very power hungry. It should be usable but don't stress it. Go to power options in control panel and press the one your using. Then go to advanced and find CPU management or something. Set the max to like 75% and you can change it after

Didn't know this was possible.

 

[Phillip Corcoran]

MERGED QUESTION
Question from siebevelez01 : "4 pin in 8 pin connector?"

Yesterday, I built myself a new computer (first time). But when I finished, I noticed that I couldn't connect my 8 pin to power the CPU, because the cable was not long enough. So, I orderer an extension cable which will arrive in like 4 days. So, i was wondering, if I could put my 4 pin in there which, weirdly, is long enough. I actually already did it and the PC did boot, but how far can I go with this 4 pin.
Specs:

i7-6700k
MSI R9 390
16gb DDR4 RAM
Z170a SLI PLUS

have no idea what 4pin and 8pin cables you are talking about.
there are 8 pin EPS (for CPU which usually comes in a 4+4) and 8 pin PCIe (for GPUs which usually comes as 6+2).
they are not compatible.