Question FPS drops, audio stutters and distortion when in high performance games

[pyskopat]

Got this problem extremely in Squad. It occurs harder when there are shootings and explosions. Temps are ok. May be interesting that my Hard drive is almost anytime at 99%.
I dont got a clue what the problem reason could be, I updated the bios, installed new chipset drivers etc.
In games like CSGO or Dead by daylight I get freezes but very rarely, e.x. when I get killed in cs the game sometimes freezes for 2-3 secs, but I almost got anytime 250-300 fps there.

My setup:
gtx 970
ryzen 2600
ddr4 3000mhz ram
and an old hdd

If u have further questions about my PC pls ask

Thanks for reading

 

[rgd1101]

upgrade to a ssd?
defrag the hdd?

 

[pyskopat]

upgrade to a ssd?
defrag the hdd?

definitely gonna do the defrag, thanks

But im still not sure if the hard drive is the real cause, because I didnt read anything like that it could be the problem. Its clearly that it makes the pc slower, but I dont know if it could really be the cause for such problems

 

[pyskopat]

defragged the hdd, problem still there

 

[pyskopat]

I guess I found the reason now.
My RAM was only at 6.3GB, even though I have 8GBs of ram. Yesterday I played almost lag free for some hours and my RAM usage was at nearly 8GB.

Pls someone could help?

 

[mdd1963]

What does task manager/performance say have in used/total available memory?