CPU usage is high

[LeHerpDeeDerp]

So for the past few months my computer has been acting up. 15% cpu usage with chrome and Skype, 60% with a twitch stream. It'd be 90% with a bf4 game, minecraft would be 60% My cpu has just been exploding. So I talked to a buddy about it, and he put his hdd into my rig, assuming I just had a virus and saving time of switching cpu's. So after his hdd was in my rig, my cpu was fantastic. I literally had 60% max with bf4 on Ultra, chrome and Skype were at 3% max alone, and twitch streams alone kept me at 30%. So we kind of decided I had a virus, or the hdd was just worn cuz it's a few years old. So I went out got a new hdd, and there was a small change, but not huge. Chrome and Skype were at a good 4% alone, twitch streams 30%, but bf4 is still it's high 90%, minecraft is 65%. Is there maybe just a setting somewhere I could change to improve this, because it was a drastic change before with his hdd. Note this was within the weekend, and I have not downloaded much besides a few games. Any help? 

 

My specs:

CPU: i5-3570K
Graphics: GTX 760SC
Motherboard: ASUS P8Z77-V LX LGA 1155 Intel Z77
HDD: 1TB WD 7200rpm
PSU: Corsair CX750 Builder Series
RAM: 8GB Corsair
CPU Fan: Intel Stock cooling fan

[PillowSmoke]

Hrm..... well for bf4 that seems like normal.

[Luc401]

Twitch uses 15% of my CPU if this helps..

[LeHerpDeeDerp]

Yea it seems normal, but why the drastic change with his hdd? He doesn't have much of anything different on it.

[Sharif]

if its a virus or something scan your computer with malwarebyte and make sure all your drivers are up to date 

[Ryan Leech]

Did you reinstall windows, or just clone the drive?

[LeHerpDeeDerp]

Well along with the new hdd, i bought windows 8.1, which he also has. And i've done virus scans, but nothin. So if there was a virus it was well-hidden, or it's just old.

[ross06187]

is our cpu changing it multiplier? ie does the clock speed keep changing.  i sounds like it might be throttling to save power and you friends hd os was on max performance with no cpu throttling.

 

you can see this in task manager in windows 8 or in cpu-z.  basically it will keep the cpu clock low but will result in high usage at lower power and lower speed