My 7700k is idling between 35-45c browsing the web with tons of tabs and youtube videos in 4K. My CPU's idle heavily depends on my room's ambient, as my room fluctuates from 70f to 76f (21-24c), when the A/C is on it's great tho since my room's Vent/Drop is aimed/angled RIGHT AT my S4 Mini
. My GPU when idling can be from 28c-34c in web browsing too. And ever since I added that low RPM BIOS mod on my 1080mini, boy is it super quiet. My a9x14 CPU fan is the loudest fan in my system and it's whisper quiet, the loudest thing at idle is the momentary spin up of the 2x 2.5inch HDDs in my S4, it's crazy how quiet the system is now.
Oh! I should probably mention that my GPU is set to adaptive performance in the NVIDIA Drivers, so it downclocks itself when idle, and it's memory is OC'ed to 11GBPs (+10% over the stock 10GBps effective clock). and has NO PROBLEM in games with that "adaptive performance" setting, as it will GPUBoost 3.0 it's way up to 2050MHz core and 11GBPs mem, no problem, barely touching 70c unless its a sustained GPU intensive section in WD2 or Zelda BoTW in 4K, in which case it might hit 73c momentarily. And my CPU will seemingly downvolt itself when idle as well, as I have c-states on in the BIOS, but I also have Intel's Turboboost on, AND I have it set in windows power setting for the CPU's miminum power state to be 100% clockspeed, so it's kinda crazy how I'm able to see it idle at the 4.5GHz turbo freq somehow (lol?), WHILE downvolting itself when idling, and keeping itself near 35c at times...
At least you know if you ever plan to upgrade, you can go my route and have an i7-K chip,
a nice Mobo with built in dual M.2
and if you drop the VRM heatsinks, you can increase your airflow and drop CPU temps.
So far my FAVORITE thing about This Kaby Lake chip (since one of the gaols of this build it 4K HDR Bluray playback) is how it EATS THROUGH h.264 and h.265 HEVC encodes, its amazing, playing a 4K or even 4K HDR Bluray rip barely touches 6-8% CPU usage and the GPU is untouched. (4K BR DRM hasn't been cracked yet, and 4K UHD Bluray drives for PC arent out yet, so i have to resort to DLing a high quality Rip of my physical 4K BR collection until the DRMs cracked and I can then begin ripping ALL my physical 4k HDR discs, so i dont have to lug around a separate 4K HDR BR Player, and can store my discs
) It's amazing how quiet it is even during super high 50MBPs video playback. Now if i start to crank up the MadVR upscaling filters in MediaPlayerClassic (for top-notch "old-school DVD" 480p to 4K upsampling), then the GPU and CPU might get pushed a bit, but it's totally within bearable temps.