CPU Temperature INSTANTLY jumps to 85-90C when stressing.

[iKingyx]

Hey guys,

So I've just swapped out my 5960X for an i7 7700k as I tend to game a lot more these days and the gaming performance was attractive. Anyway. I've Overclocked my chip to 5Ghz with 1.375V. I'm using the H100i v2 cooler and when stressing my chip to check if stable, it goes from idle around 38-40C instantly, I'm not talking delay of a second as it increases, instantly jumps to 85-90C. The second I stop the stress it instantly drops back to 40C. No gaps between.

When hovering my hand above the cooler radiator which is an exhaust, no heat, just nice cool air, any ideas why this is the case? System seems stable after letting the stress run for 10 mins however I'm sceptical to leave it any longer showing me these temps.

Thanks in advance,
Kingy

 

[CountMike]

That usually signifies bad CPU cooler/water block mounting or badly applied paste.

 

[GhislainG]

What stress test? Depending on the stress test, 85-90°C may be excellent.

 

[CountMike]

What stress test? Depending on the stress test, 85-90°C may be excellent.

The point was very FAST temperature jump.

 

[GhislainG]

What stress test? Depending on the stress test, 85-90°C may be excellent.

The point was very FAST temperature jump.

Running the current version of Prime95 Small FFTs will heat the CPU very fast. The OP didn't quantify what is meant by instantly, but I doubt it's milliseconds.

Edit: A graph generated with Intel XTU (all hardware monitors active) may be useful.

 

[CountMike]

I was going by this "it goes from idle around 38-40C instantly, I'm not talking delay of a second as it increases, instantly jumps to 85-90C." Water cooling is very slow to change temp up or down. Some fast small change is possible but newer to the max, after that it levels and raises/fall slowly. Only if heat transfer is bad would be fast. Even notoriously hot when OCed, FX processor at high frequency takes 10 seconds or more to hit highs.