Lag/Freeze/FPS Drop Playing Games

[RedJosh94]

Hello, i have a very irritating problem with my system when playing games. When i play anything from stalker to company of heroes 2, every now and then the game will freeze for a split second and the frame rate will drop from very high to very low then go all the way back up again. Also when this happens the computer itself makes a noise also for a split second. My system is pretty good spec so i don't understand what is causing this. I also use good hdmi leads.
SPEC:
I54690k with arctic cooler fan (havent even overclocked yet)
MSI r9270x GPU
msi gaming motherboard G45
8gb team elite RAM
1 TB hard drive
power supply is unknown (though as it came with my case so i think this could be a factor, but it is 750w so should be fine power wise)

Also the computer is quite loud even when not playing games. It doesnt sound like fan noise, but more like a general electric noise, it is very hard to describe the sound to you all.
Any help would be appreciated, Thanksssssssssss

 

[Gracodana]

most likly the psu dont use bundled psu's in general even if it's going to be enough to power your system

 

[Cons29]

most psu's that comes with the case are not good, most of what i've seen at least. so it's worth a check

while playing, monitor temperature to at least rule out temp issues. you can also monitor utilization