Main Content


Namespace: parallel.gpu

Manager for GPU Devices


parallel.gpu.GPUDeviceManager broadcasts events that indicate when a GPU device is selected, deselected, or reset. Use parallel.gpu.GPUDeviceManager to set up notifications that inform you when your GPU device is selected, deselected, or reset without having to call gpuDevice or monitor data stored on the GPU. You can also use parallel.gpu.GPUDeviceManager to automatically change your GPU settings when a GPU is selected.




gdm = parallel.gpu.GPUDeviceManager.instance accesses the GPU device manager gdm that broadcasts events that indicate when a GPU device is selected, deselected, or reset.


You can only use one instance of parallel.gpu.GPUDeviceManager available in a given MATLAB session.


expand all

The selected GPU device, specified as a GPUDevice object. If no GPU device is selected, then the property is an empty GPUDevice array.




expand all


Event NameTriggerEvent DataEvent Attributes
DeviceSelectedTriggered after a GPU device is selected.



  • DeviceIndex - Index of the selected GPU device.

NotifyAccess: private

ListenAccess: public

DeviceDeselectingTriggered just before a GPU device is deselected.



  • DeviceIndex - Index of the GPU device being deselected.

NotifyAccess: private

ListenAccess: public


When you reset a GPU device, the software triggers DeviceDeselecting and then DeviceSelected.

For more information about using events, see the examples on this page and Overview Events and Listeners.


collapse all

Create a parallel.gpu.DeviceManager object.

gdm = parallel.gpu.GPUDeviceManager.instance
gdm = 
  GPUDeviceManager with properties:

    SelectedDevice: [0×0 parallel.gpu.CUDADevice]

Select a GPU device and use the GPU device manager to inspect the selected GPU device.

gpu = gpuDevice;
ans = 
  CUDADevice with properties:

                      Name: 'NVIDIA RTX A5000'
                     Index: 1
         ComputeCapability: '8.6'
            SupportsDouble: 1
     GraphicsDriverVersion: '528.24'
               DriverModel: 'TCC'
            ToolkitVersion: 11.8000
        MaxThreadsPerBlock: 1024
          MaxShmemPerBlock: 49152 (49.15 KB)
        MaxThreadBlockSize: [1024 1024 64]
               MaxGridSize: [2.1475e+09 65535 65535]
                 SIMDWidth: 32
               TotalMemory: 25544294400 (25.54 GB)
           AvailableMemory: 25129254912 (25.13 GB)
               CachePolicy: 'balanced'
       MultiprocessorCount: 64
              ClockRateKHz: 1695000
               ComputeMode: 'Default'
      GPUOverlapsTransfers: 1
    KernelExecutionTimeout: 0
          CanMapHostMemory: 1
           DeviceSupported: 1
           DeviceAvailable: 1
            DeviceSelected: 1

Create a parallel.gpu.DeviceManager object.

gdm = parallel.gpu.GPUDeviceManager.instance;

Create callback functions that the software calls when a GPU device is selected or about to be deselected. These functions display the device index of the GPU and whether it has been selected or deselected. Even if they are not used, callback functions must define at least two input arguments: the event source and the event data. For more information, see Overview Events and Listeners.

selectedMessage = @(source,event) disp("GPU device " + event.DeviceIndex + " selected.");
deselectedMessage = @(source,event) disp("GPU device " + event.DeviceIndex + " deselected.");

Create event listeners, bound to the DeviceSelected and DeviceDeselecting events of the GPU device manager gdm, that call the callback functions.

selectedListener = listener(gdm,"DeviceSelected",selectedMessage);
deselectedListener = listener(gdm,"DeviceDeselecting",deselectedMessage);

To check that the callback functions and listeners are configured correctly, select and deselect your GPU.

GPU device 1 selected.
GPU device 1 deselected.

To remove the listeners, delete the listener objects.


Create a parallel.gpu.DeviceManager object.

gdm = parallel.gpu.GPUDeviceManager.instance;

Create a function handle to the setCachePolicy function. The setCachePolicy function, defined at the end of this example, changes the caching policy of the selected GPU to 'maximum'.

selectedFcn = @(source,event) setCachePolicy(source);

Create an event listener, bound to the DeviceSelected event of the GPU device manager gdm, that calls the callback function selectedFcn. The software sets the caching policy to 'maximum' when a new GPU device is selected. The cachePolicy property of a gpuDevice object determines how much GPU memory can be cached to accelerate computation.

selectedListener = listener(gdm,"DeviceSelected",selectedFcn);

To check that the callback function and listener are configured correctly, deselect any already selected GPUs, then select your GPU and inspect its CachePolicy property.

gpu = gpuDevice;
NVIDIA RTX A5000 GPU selected.
Current caching policy: balanced
Setting caching policy to maximum.
ans = 

To remove the listener, delete the listener object.


Set Cache Policy Function

The setCachePolicy function receives a GPU device manager object source and changes the caching policy of the currently selected GPU device.

function setCachePolicy(gdm)

% Display selected GPU name and caching policy.
disp(gdm.SelectedDevice.Name + " GPU selected.")
disp("Current caching policy: " + gdm.SelectedDevice.CachePolicy)

% Set the caching policy to maximum.
disp("Setting caching policy to maximum.")
gdm.SelectedDevice.CachePolicy = "maximum";


Extended Capabilities

Version History

Introduced in R2016a