Msi gtx 560ti hawk running always max clocks

Question

Hello.
My msi gtx 560ti hawk running always max clocks.
OC core clock up to 1000MHz gives similar results.
OC core clock past 1000MHz will stuck it at 1000MHz. Example i set core clock to 1040MHz and run 3DMark11,but
during the test it never exceeds 1000MHz.
Card is 15 months old and worked normally so far.
My OC results before was
core clock 1000MHz Core Voltage 1.075V
core clock 1040MHz Core Voltage 1.088V
core clock 1100MHz Core Voltage 1.100V max temps ~78C
I never raised core clock over 1100 and memory clock over 2275.
Things i'm done so far
used 310.90 310.70 306.97 306.23 301.42 drivers
disabled antivirus
mounted card out of the case and switched vbios in silence mode
used Afterburner 2.2.3 Evga Precision X
reinstalled windows7
reverted cpu to stock clocks
Any advice?
System
MB: msi z68-gd65 (B3) bios V22.8
cpu: i5-2500K
gpu: msi gtx 560ti hawk
psu: corsair TX750V2 (62 amp 12 rail)
ram: G.Skill F3-12800CL9D-8GBXL 2x4g 1600
os: Windows7 SP1

Answer 1

No! Nvidia controlpanel was set to max perfomans and windows power options to high perfomance.
 I changed nvidia to adaptive (windows stayed high perf) and now the clocks to come down again.
Thanks Svet!
There is still a OC problem when i set core clock over 1000MHz.
I just ran 3dmark11 at following overclock core     1040MHz
                                                              shader 2080MHz 
                                                              memory 2100
                                                              core voltage 1.075+0.013
In results window the 3dmark11 says core clock 1040.                                   
Afterburner 2.3.1 monitoring window says max core clock 1000
                                                                          shader 2000 
                                                                          memory 2099
Although i´m not seeing shader adjusting bar in 2.3.1, there are  only core clock adjusting bar.
But adjusting a core clock will adjust shader x2. Am i right?