8700K Temps jumping around

[Lunardoom]

I know this has prob been asked 1000 times. Let me first state this is my first build in almost 10 years!!! My first build was an I7 860! So ive pretty much stuck with the same everything/brand just newer versions! So I have an i7 8700k, Asus Maximus X Code,H100i V2 and 750D case (non air flow Edition) So when i built the computer I placed the rad up top with Fans Exhausting Pulling air from in the case Exhausting out the top as per the directions. I stuck with the thermal paste that was on the H100i v2 as i heard it was actually really good. I noticed my Temps idle were between 32-36c but bouncing around up to 50c when i was doing light work like watching you tube, but not staying there, but i would see something like 30, 31, 40, 50, then back down to 30s, but this would happen with in like 5 seconds. So i swapped the rad to the front. I kept the 140s on the front that came w/ the 750d and just mounted the rad to the bracket and put my Ml120s so i guess its push/pull. I did notices a slight drop to 30-32c, but its still doing the same, just small spikes up to 45c with no load. I am new to this processor is this ok? I haven't reseat the cooler yet. I did order some new artic silver to see if it will help. Also with this case is the rad ok in the front? Everywhere i read they say u want fresh/cool air pulling into the rad, but i dont get alot of people put it up top for exhaust, but at that point arnt you just pulling hot air thru the rad? Can some one give me some pointers? ya ive watched videos and read and it seems to be 50/50 on the placement.

[c-attack]

Welcome to the new Intel. This is absolutely normal for Kaby and Coffee Lake processors. If you watch the multiplier at the same time it will increase with those core temp variances. These recent CPUs are tuned to provide a lot of desktop responsiveness and while my 5930K will sit quietly and wait for commands, my 8700K bounces around in its socket like a 6 year old waiting for recess. You may also want to see what the Vcore is doing if you are using Auto or Adaptive voltage. The standard settings for Asus boards will really pile on the voltage in some unnecessary situations. I can't remember if they finally changed it, but originally all the Asus Z370 boards defaulted to a hidden "worst case scenario" as the "default" setting under CPU behavior. If you have not read it, the Asus OC guide for Kaby/Coffee Lake has more info than you need, but also some critical points. If using Adaptive, you must set those IA/DC load line voltages (page 3) to 0.01. It is ridiculous if you don't. Also, set the CPU behavior thing at the top to either Best case or normal to keep the Vcore padding to a minimum. You can turn up higher C-states and power saving features to neutralizer the desktop variances, but it then does require some power management when you are doing performance tasks like gaming. While the multiplier will still bounce, once the Vcore is stabilized your core temps should as well.