... i5 4690k ... performance has dropped considerably ... 97C ... changed the thermal paste ... now it's 84-85C with a few spikes to 88C ... idle core temperatures vary from 38C to 52C. Not overclocked ... fan RPM was around 1900RPM idle on BIOS ... cpu seems to be underperforming, in the 27th percentile ...
Caedite,
On behalf of Tom's Moderator Team, welcome aboard!
It's highly likely that your stock cooler has a push-pin problem.
The push-pins can be deceivingly tricky to get them fully inserted through the motherboard, completely seated and properly latched. Even the most experienced of us have made the same mistake, so you're in good company. A loose push-pin 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.
When working with push-pins, take your time and closely examine each individual push-pin. Use a strong light and compare it to its neighbors. If you can access the back of the socket, inspect both sides of the motherboard so you can scrutinize the tips of each push pin.
(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.
Intel Stock Cooler Installation -
View: https://www.youtube.com/watch?v=5qczGR4KMnY
If you're considering replacing your stock cooler, then keep in mind that coolers with push-pins should be avoided in favor of coolers which use proper fastening hardware with a back-plate.
Once again, welcome aboard!
CT