nakita2004piatrenk,
Your Be Quiet Pure Rock Slim, like Intel's stock cooler, is a push-pin cooler. All push-pin coolers are problematic and should be avoided in favor of coolers that have proper fastening hardware with a back plate.
It's very likely that your Pure Rock Slim has popped a push-pin loose from the motherboard, which is a very common problem. This causes poor contact pressure between the cooler and the CPU, resulting in high temperatures in BIOS, as well as in Windows at idle, and especially at 100% workload.
You can troubleshoot this problem by pushing firmly on each corner of the cooler for about 30 seconds while watching your load temperatures. When you see a significant drop, you've found the loose push-pin.
The push-pins can be deceivingly tricky to get them fully inserted through the motherboard and properly latched.
(1) To re-seat a single loose push-pin, rotate the latch mechanism in the direction of the arrow counterclockwise 90° then retract the pin by pulling upward. Rotate the latch clockwise 90° to reset the pin, but do NOT push on the latch yet.
(2) To get the pin fully inserted through the motherboard, push only on the leg, NOT on the top of the latch.
(3) While holding the leg firmly against the motherboard with one hand, you can now push on the top of the latch with your other hand until the latch clicks.
(4) If you're re-seating the entire cooler, then be sure to latch the pins across from one another, rather than next to one another. Use an "X" pattern, so as to apply even pressure during installation.
Just to serve as a generic example to use on your Pure Rock Slim, here's a video for dealing with the push-pins on an Intel stock cooler Installation -
View: https://www.youtube.com/watch?v=5qczGR4KMnY
CT