New PC Feels like it's severely under performing.

[Wang Chung]

My PC specs are:

MSI H170 Gaming M3 Motherboard (DDR4-SDRAM, DIMM, Serial ATA III)
Intel Core i7 Quad-Core i7-6700 3.4GHz Processor CPU
GIGABYTE NVIDIA GeForce GTX 1080 G1 GAMING
Corsair CP-9020061-UK Builder Series CXM750 ATX/EPS Semi-Modular 80 PLUS Bronze Power Supply Unit, 750 W
Corsair CMK16GX4M2A2666C16W Vengeance LPX 16 GB (2 x 8 GB) DDR4 2666 MHz XMP 2.0 High Performance Desktop Memory Kit - White
WD Black 4TB Performance Desktop Hard Disk Drive - 7200 RPM SATA 6 Gb/s 64MB Cache 3.5 Inch
Samsung 850 EVO 250 GB 2.5 inch Solid State Drive - Black

I recently bought these for a new system but my FPS starts to drop over time in certain games that I thought a system like this would be able to deal with, with ease (Overwatch, Black Desert Online, League of Legends)

For example I start up a LoL match and i get 300-400 FPS and then it'll gradually drop and fluctuate untill it gets to sub 100, its not that i need the frames but its the fluctuation seems odd instead of staying at a constant figure and for games like Overwatch and BDO the FPS starts at 60-100 and will slowly drop untill it gets to a point where the frames are at 20 and it becomes awful to play.

I've monitored temps via HWMonitor and the CPU gets towards 70c which is fairly hot so could it simply be the CPU getting a tad hot ? I'm not very clued up on computers so i find it hard identifying issues.

Any help would awesome, much love.

 

[salerhino]

Yeah, CPU is warm and it might be CPU throttle causing the issue, so please clean dust,reapply thermal paste and check on what speed is fan spinning.