DeadlyMercury
"A faster cpu" - are you really comparing 6700k to phenoms and buldozers? :)

No, it was an example to show that faster cpus help.

"Lag spikes?" Do you mean stuttering and hitching? If its happening in fortnite on low then it sounds like a drive issue. Are you running an SSD or an old mechanical hard drive?
 
You said that you haven't performed a wipe in over 4 years.   You should wipe your hard drive and reinstall windows every 12 months or so.  It's just good practice.

i am using an ssd, https:  //www.userbenchmark.com/UserRun/   26369797
he is the link for my userbenchmark,you can see there my ssd speed etc. what can i do to stop the lag spikes?

That mean only that officially something more than 2133mhz is not supported, everything upper is overclock. But difference between 2133 and 2400 is not so high to fail. Maybe timings is incorrect or something like that.
Sandy bridge for example supports only 1333 mhz memory, but actually can run up to 2133 or at leas 1866. Same for coffee lake - supports up to 2666 mhz - actually can be set up to 3200-3600 without any problems. You could try to set your RAM speed and timings mannually, but that will not give you much difference.
 

hatz12337
what can i do to stop the lag spikes?

you need to investigate what happens with your system when this lags occurs. Try run task manager and resourse manager at least to see if any suspisious activity is occurs. Also you can use msi afterburner and check what happens to your gpu (load, clocks etc).
Also it should be mentioned that fortnite is based on Unreal Engine 4 which is not perfect and quite old. For example:
https://www.reddit.com/r/FortniteCompetitive/comments/ezqioo/reason_for_fps_drops_after_v1150/- same problem, so it is not bounded to your pc and actually happend due to game engine (again).
 

also what should i look up to?nothing seems to be unnormal

i just tried to play some cs:go and i have unexpected low fps,yesterday i had 350+ and now 130?!!!
heres a photo of it: https: //imgur.com/a/ mc3MKTR

That was a joke, about low quality of asus software.
And also lowered fps could mean some fps cap, for example evga x1 does have this feature, maybe asus tweak does this too.

Well, there is nothing happend with gpu at all (little power consumption drop, but that is not a big deal, gpu load stayed), and the only thing you can notice is a temperature drop on some cpu cores at the same time.
That could mean that core stopped it work at this momend, it can happen if thread that is running on this core waiting for something, usually IO (disks, RAM etc).
 
So it could be related to some disk activity (task manager, process manager disk spikes?), or just game did something wrong (like stopping all threads and running garbadge collector, if it were some JVM-based software :) ).
If there is some disks spikes - you could try to identify proccess with resourse manager.
For example, this issue:
https://fortniteintel.com/epic-to-address-fortnite-fps-problems/30136/
Does they solved this? Task is still opened.

yes, but it is also depend on if this speed consistent or if compression enabled for drive.
but even with old ssd with enabled compressions (which limits disk performance to 100-150mbps) there should be no troubles with any games plus most of game files should be in the memory already, so there should be no waiting for reading disk.
 
but I found somebody said that fortnite do some random writes, I don't know if its truth though:
https://forums.tomshardware.com/threads/fps-drops-on-fortnite.3527318/
 
**still this is kind of overhead idea to get an optane ssd for fortnite lol

and you don't play gta5 either? :)