huge fps drops for a second

i have a new pc its 2 weeks old every times i play heroes of newarth and wow ( i havent tried any other games ) 50+ fps and randomly it drops to 20 and it is really anoying i have amd fx 6100 and gtx 660 8g ram 1600mhz windows 7
my gpu temp is normal (32) and my cpu usage in hon was 17% but i have noticed that the first core is 100% and the rest had not much usage but didnt check this in wow but i doubt this is the case

i have gpu driver 331.82 ( this is the latest ) and tried to downgrade to check if the driver is the problem so went down to 306 and still the problem exist tunred off my firewall and windows defender and delete my kaspersky and still nothing

my cpu z tells me i have 8 g ram with 800 mhz
thx helper and have a nice day

Use http://www.techpowerup.com/realtemp/

play your games, when you see the sudden drop in fps alt+tab to see what's your temp

Do the same thing with your GPU temp http://www.gputemp.com/

I have an ATI so I just use my Catalyst Control Center.

install MSI afterburner+ Hwinfo64 and enable in-game monitoring GPU and Cpu usage as well as Gpu and Cpu temps and see what the culprit is. Does that heppens when there are a lot of enemies on screen. Mind you a first gen FX6xxx series Cpu will bottleneck something like Gtx660ti on games that are not well threaded ( and if i remember correctly wow is not exactly a poster child when comes to cpu optimization and fast dual core will be much more suited for wow compared to a cpu that while better at multithreading has worst single core performance )