Maybe it's an internet issue?

Edit: Sometimes when ppl stream movies at my place, I have an ok ping but it stutters a bit.

open up TF2 in windowed mode, keep task manager to the side as you play and have it sort by CPU usage (so the most usage is at the top)

whenever it stutters, you should end up seeing the process fucking shit up

I noticed that my CPU was working way too hard - 95-100% usage, along with 90-95% usage on my ram

Furthermore, my cpu was pretty hot- 53 C, which is super hot for what it normally is.

it won't throttle anywhere near that

do you play borderless or full screen normally? and what OS?

also with that much CPU usage there must be something else going on in the background. what other processes are using the CPU? screenshot task manager's Processes (7) or Details (8, 10) tab, sorting by CPU usage

53°C on load is normal. cpu and ram usage too..would it be weird not having a full load on the cpu while playing tf2. not a hardware issue it seems more like a networking problem..especially since you get lag spikes when downloading music with spotify. also don't monitor hw usage with games in windowed mode, rendering works better in fullscreen mode. instead you can use cpu_frequency_monitoring 1 and net_graph 1 (0 for both to disable them). Both will show on screen and you can monitor networking and hw usage at the same time. Now, when you experience stutters check for ping, cl_updaterate value (it's the second number from the top in the far right column in the net_graph) and the cpu frequency and usage percentage. if your ping raises and\or the updaterate drops while stuttering then you got network issues > some processes on your pc or other users in the network are using internet bandwidth (DL or UL). If network values are fine but you see the cpu percentage getting lower and lower then you got thermal throttling issues. I don't think that's the case, highest allowed temperature for that chip is 72°. source: intel cpu page.

The music that I play in the background with spotify is saved offline, so it's not a networking thing. It's definitely not a networking thing, since this doesn't happen in CS.

i see, i don't use spotify but the network-hardware check via net_graph could still be worth it. maybe some other software are causing that network lag..is it constant or does it happen after few minutes of playing? i'd check if some recent changes to your system may have corrupted something. i had an issue like this and it turned out it was caused by the windows paging file size. had to put it back to automatic - windows managed..also bad networking values in a tf2 cfg can produce stutters. like cl_smooth 0, cl_smoothtime, cl_pred_optimize and stuff like that

Here is my cfg:

autoexec: http://pastebin.com/wsqVDyfG
config file: http://pastebin.com/4wHUa2rz

I've disabled hibernation mode and the massive amount of memory that takes up.

in your autoexec.cfg find these parameters and change their values like so:

cl_interp 0.033
cl_interp_ratio 2
cl_smooth 1
cl_smoothtime 0.1

about paging file size follow this

just go from point 1 to 6 and make sure "automatically manage paging file size for all drives" is checked. it should already be if you haven't messed up with it, i think.