Glxgears different framerate Tesla T4

Hi,
I’m working on AWS cloud with T4 instances. My application needs OpenGL rendering so I have to run X server. I noticed that after reboot or some idle time when I run glxgears it starts with low framerate ~ 450 FPS. When I exit process and run it once again it has normal framerate ~32000FPS. I don’t see that on V100 and Azure - it has always same rate. What can be cause of such different results?

Driver on AWS: 510.73.05, nouveau blacklist
Xorg.conf:

# nvidia-xconfig: X configuration file generated by nvidia-xconfig                                                                                                                                         
# nvidia-xconfig:  version 510.73.05                                                                                                                                                                       
                                                                                                     
                                                                                                     
Section "ServerLayout"                            
    Identifier     "Layout0"                                                                         
    Screen      0  "Screen0"                                                                         
    InputDevice    "Keyboard0" "CoreKeyboard"                                                        
    InputDevice    "Mouse0" "CorePointer"                                                            
    Option         "AllowNVIDIAGPUScreens"                                                           
EndSection                                        

Section "Files"                                   
EndSection                                        

Section "InputDevice"                             

    # generated from default                                                                         
    Identifier     "Mouse0"                                                                          
    Driver         "mouse"                                                                           
    Option         "Protocol" "auto"                                                                 
    Option         "Device" "/dev/psaux"                                                             
    Option         "Emulate3Buttons" "no"                                                            
    Option         "ZAxisMapping" "4 5"                                                              
EndSection                                        

Section "InputDevice"                             

    # generated from default                                                                         
    Identifier     "Keyboard0"                                                                       
    Driver         "kbd"                          
EndSection                                        

Section "Monitor"                                 
    Identifier     "Monitor0"                                                                        
    VendorName     "Unknown"                                                                         
    ModelName      "Unknown"                                                                         
    Option         "DPMS"                                                                            
EndSection                                        

Section "Device"                                  
    Identifier     "Device0"                                                                         
    Driver         "nvidia"                                                                          
    VendorName     "NVIDIA Corporation"                                                              
    BoardName      "Tesla T4"                                                                        
    BusID          "PCI:0:30:0"                                                                      
EndSection                                        

Section "Screen"                                  
    Identifier     "Screen0"                                                                         
    Device         "Device0"                                                                         
    Monitor        "Monitor0"
    VendorName     "Unknown"                                                                         
    ModelName      "Unknown"                                                                         
    Option         "DPMS"                                                                            
EndSection                                                                                           
                                                  
Section "Device"                                  
    Identifier     "Device0"                                                                         
    Driver         "nvidia"                                                                          
    VendorName     "NVIDIA Corporation"                                                              
    BoardName      "Tesla T4"                                                                        
    BusID          "PCI:0:30:0"                                                                      
EndSection                                                                                           
                                                  
Section "Screen"                                  
    Identifier     "Screen0"                                                                         
    Device         "Device0"                                                                         
    Monitor        "Monitor0"                                                                        
    DefaultDepth    24                                                                               
    Option         "AllowEmptyInitialConfiguration" "True"                                                                                                                                                 
    SubSection     "Display"                                                                         
        Virtual     1280 1024                                                                        
        Depth       24                            
    EndSubSection                                 
EndSection