If it's been running hotter and hotter over time, the cooler fins may just be getting plugged with dust..I would start by getting some canned air and blow back through it and pick the dust bunnies out through the fan with tweezers best as possible, or you could disassemble it and clean the cooler fins and replace the TIM without voiding the warranty (provided you don't damage anything)..I wouldn't think the TIM would be an issue though seeing as it's only about a year old..You can also make an aggressive custom fan profile with Precision X or MSI Afterburner to help keep it more cool.

so jumped into dayz and I could hear the fans screaming!!   ran around for about 5minutes and hit a max temp of 78.  That just seams too high.  

Thanks for the advice.  I did just pull out the vid card and blew out the fan.  Its an older model card and the cooling on it looks pretty crummy compared to others I have seen.  Barely any dust came out.  I do have a 144hz monitor.  I think thats kind of interesting.  My other fans are pretty clean. I have a H60 that I blew them fans out just last week.  Im using Hardware monitor and not sure which reading would be my ambient temp.  Played dayz for a little bit and my max is at 73.  Little better... 
 
Just thought I'd mention my firestrike score on 3dmark is pretty weak considering my system no?    bahhh... cant post a link.      add the h  ttp://www.3dmark.com/fs/1532994
 
 

83C is really high for a 760(which is basically a re-branded 670. My 2 670 FTWs rarely break 55C ever, even when 144% pwr target is reached, at 100% load. I would say look at your cooling solution, meaning case/fans air flow etc. I have 7 fans in my tiny mid tower ATX and have some of the lowest gpu temps without going under water.