GPU trouble

[TTurnerdudEE]

Hi, So I launched the Dayz (No idea if this is relevant or not to the issue) and started playing, For about 2-4 minutes it was totally fine , But then all of a sudden my frame rate dropped dramatically for no apparent reason, So I tabbed out to check MSI afterburner to see what was the matter and on the core clock graph it dropped from what I was running (It has been able to run at this clock beforehand absolutely fine) to about half it, The temperatures on the temp graph were rising as I had been playing but had not reached anything absurd with a max gpu temp of 68 degree Celsius , 

If it helps this is what its stock speed is at and what I was running it at and then what it dropped to:

Stock :

voltage: 1012

clock: 856 Mhz

Shader: 1712 Mhz

memory: 2084Mhz

Oc'd:

stock: 

voltage: 1025

Clock: 972 Mhz

Shader: 1944 Mhz

Memory: 2251 Mhz

Dropped to while playing:

Clock: 401 Mhz

and everything else dropped accordingly 

 

If anyone could please help identifying the issue at hand, Is it my overclock? is it a heat issue? or is it a game bug?

Also when I tabbed back into game the clock speed did not increase but stayed at 401 Mhz 

 

Thank you, 

- Tristan. 

 

 

[Jodomcfrodo]

What GPU?

[TTurnerdudEE]

GTX 560 ti (gainward phantom)