Is my GPU dying?

I temporarily disable ECC memory protection on a NVIDIA K20m (device 0 in my node) and now I cannot bring it back to work again. Before that it was working properly with ECC enabled. So, here is what I did: I disabled ECC with

nvidia-smi -i 0 --ecc-config=0

and rebooted. When it came up it showed 100% GPU utilization and it wouldn't start any kernels (it actually already failed when creating the context). The reason was a double bit error. I reset it with

nvidia-smi -i 0 --reset-ecc-errors=0

and rebooted the node. After the reboot the device utilization was 0% and I could start jobs as usual. A few hours later the device showed again a 100% GPU utilization. This time it didn't report a double bit error (not even a single bit error). However, since I couldn't run any job I rebooted the node and it came up with 100% GPU utilization, I can't use it, but reports no bit errors. What's the matter this it?

GPU 0000:02:00.0
    Product Name                : Tesla K20m
    Display Mode                : Disabled
    Persistence Mode            : Enabled
    Driver Model
        Current                 : N/A
        Pending                 : N/A
    Serial Number               : 0324512044699
    GPU UUID                    : GPU-9bfe1aba-1628-a406-3ed5-2af49462a997
    VBIOS Version               : 80.10.11.00.0B
    Inforom Version
        Image Version           : 2081.0208.01.07
        OEM Object              : 1.1
        ECC Object              : 3.0
        Power Management Object : N/A
    GPU Operation Mode
        Current                 : Compute
        Pending                 : Compute
    PCI
        Bus                     : 0x02
        Device                  : 0x00
        Domain                  : 0x0000
        Device Id               : 0x102810DE
        Bus Id                  : 0000:02:00.0
        Sub System Id           : 0x101510DE
        GPU Link Info
            PCIe Generation
                Max             : 2
                Current         : 2
            Link Width
                Max             : 16x
                Current         : 16x
    Fan Speed                   : N/A
    Performance State           : P0
    Clocks Throttle Reasons
        Idle                    : Not Active
        User Defined Clocks     : Not Active
        SW Power Cap            : Not Active
        HW Slowdown             : Not Active
        Unknown                 : Not Active
    Memory Usage
        Total                   : 4799 MB
        Used                    : 12 MB
        Free                    : 4787 MB
    Compute Mode                : Default
    Utilization
        Gpu                     : 100 %
        Memory                  : 0 %
    Ecc Mode
        Current                 : Enabled
        Pending                 : Enabled
    ECC Errors
        Volatile
            Single Bit            
                Device Memory   : 0
                Register File   : 0
                L1 Cache        : 0
                L2 Cache        : 0
                Texture Memory  : 0
                Total           : 0
            Double Bit            
                Device Memory   : 0
                Register File   : 0
                L1 Cache        : 0
                L2 Cache        : 0
                Texture Memory  : 0
                Total           : 0
        Aggregate
            Single Bit            
                Device Memory   : 0
                Register File   : 0
                L1 Cache        : 0
                L2 Cache        : 0
                Texture Memory  : 0
                Total           : 0
            Double Bit            
                Device Memory   : 0
                Register File   : 0
                L1 Cache        : 0
                L2 Cache        : 0
                Texture Memory  : 0
                Total           : 0
    Temperature
        Gpu                     : 30 C
    Power Readings
        Power Management        : Supported
        Power Draw              : 49.51 W
        Power Limit             : 225.00 W
        Default Power Limit     : 225.00 W
        Min Power Limit         : 150.00 W
        Max Power Limit         : 225.00 W
    Clocks
        Graphics                : 758 MHz
        SM                      : 758 MHz
        Memory                  : 2600 MHz
    Applications Clocks
        Graphics                : 705 MHz
        Memory                  : 2600 MHz
    Max Clocks
        Graphics                : 758 MHz
        SM                      : 758 MHz
        Memory                  : 2600 MHz
    Compute Processes           : None

Is my GPU dying?

I say it's already dead. It's no longer reporting bit errors because you turned off the thing that detects them. (ECC detects more than it can correct.) However, it may be the memory on the card (or the physical card itself) that's developed a fault.

There's two other suspects before I'd chuck it in the "recycle" bin: cooling, and power supply. Cooling is easy enough to check; power, not so much.