I'm trying to retrieve GPU temperature information using the code below (not mine; slightly modified), but get a 'false' return when I attempt to call the .dll function, nvCplGetThermalSettings:
HINSTANCE lib = LoadLibraryA("nvcpl.dll");
if(lib)
{
NvCplGetThermalSettings nvCplGetThermalSettings = reinterpret_cast<NvCplGetThermalSettings> (GetProcAddress(lib,"NvCplGetThermalSettings"));
DWORD coreTemp,ambientTemp,upperLimit;
int success = nvCplGetThermalSettings(0,&coreTemp,&ambientTemp,&upperLimit);
if(!success) {
printf("Call failed: %d\n", success);
}
else {
char text[128];
printf(
"Core Temp: %d°\n"
"Ambient Temp: %d°\n"
"Upper Limit: %d°",coreTemp,ambientTemp,upperLimit);
}
FreeLibrary(lib);
}
else {
printf("Couldn't load library.\n");
}
The .dll is being loaded, is relatively up to date (2013), and applications such as GPU-Z are able to display this information, so I know it's not a hardware/driver issue. Any ideas appreciated in advance.
In case anyone else was interested in the solution, using nvapi64.dll did the trick, but required replicating a few structs using non-API-specific objects and some digging through headers. Functional code is as follows:
#include <windows.h>
#include <iostream>
#define NVAPI_MAX_THERMAL_SENSORS_PER_GPU 3
typedef enum
{
NVAPI_THERMAL_TARGET_NONE = 0,
NVAPI_THERMAL_TARGET_GPU = 1, //!< GPU core temperature requires NvPhysicalGpuHandle
NVAPI_THERMAL_TARGET_MEMORY = 2, //!< GPU memory temperature requires NvPhysicalGpuHandle
NVAPI_THERMAL_TARGET_POWER_SUPPLY = 4, //!< GPU power supply temperature requires NvPhysicalGpuHandle
NVAPI_THERMAL_TARGET_BOARD = 8, //!< GPU board ambient temperature requires NvPhysicalGpuHandle
NVAPI_THERMAL_TARGET_VCD_BOARD = 9, //!< Visual Computing Device Board temperature requires NvVisualComputingDeviceHandle
NVAPI_THERMAL_TARGET_VCD_INLET = 10, //!< Visual Computing Device Inlet temperature requires NvVisualComputingDeviceHandle
NVAPI_THERMAL_TARGET_VCD_OUTLET = 11, //!< Visual Computing Device Outlet temperature requires NvVisualComputingDeviceHandle
NVAPI_THERMAL_TARGET_ALL = 15,
NVAPI_THERMAL_TARGET_UNKNOWN = -1,
} NV_THERMAL_TARGET;
typedef struct
{
int version; //!< structure version
int count; //!< number of associated thermal sensors
struct
{
int controller; //!< internal, ADM1032, MAX6649...
int defaultMinTemp; //!< The min default temperature value of the thermal sensor in degree Celsius
int defaultMaxTemp; //!< The max default temperature value of the thermal sensor in degree Celsius
int currentTemp; //!< The current temperature value of the thermal sensor in degree Celsius
NV_THERMAL_TARGET target; //!< Thermal sensor targeted @ GPU, memory, chipset, powersupply, Visual Computing Device, etc.
} sensor[NVAPI_MAX_THERMAL_SENSORS_PER_GPU];
} NV_GPU_THERMAL_SETTINGS;
// magic numbers, do not change them
#define NVAPI_MAX_PHYSICAL_GPUS 64
#define NVAPI_MAX_USAGES_PER_GPU 34
// function pointer types
typedef int *(*NvAPI_QueryInterface_t)(unsigned int offset);
typedef int (*NvAPI_Initialize_t)();
typedef int (*NvAPI_EnumPhysicalGPUs_t)(int **handles, int *count);
typedef int (*NvAPI_GPU_GetUsages_t)(int *handle, unsigned int *usages);
typedef int (*NvAPI_GPU_GetThermalSettings_t)(int *handle, int sensorIndex, NV_GPU_THERMAL_SETTINGS *temp);
int main()
{
HMODULE hmod = LoadLibraryA("nvapi64.dll");
if (hmod == NULL)
{
std::cerr << "Couldn't find nvapi.dll" << std::endl;
return 1;
}
// nvapi.dll internal function pointers
NvAPI_QueryInterface_t NvAPI_QueryInterface = NULL;
NvAPI_Initialize_t NvAPI_Initialize = NULL;
NvAPI_EnumPhysicalGPUs_t NvAPI_EnumPhysicalGPUs = NULL;
NvAPI_GPU_GetUsages_t NvAPI_GPU_GetUsages = NULL;
NvAPI_GPU_GetThermalSettings_t NvAPI_GPU_GetThermalSettings = NULL;
// nvapi_QueryInterface is a function used to retrieve other internal functions in nvapi.dll
NvAPI_QueryInterface = (NvAPI_QueryInterface_t) GetProcAddress(hmod, "nvapi_QueryInterface");
// some useful internal functions that aren't exported by nvapi.dll
NvAPI_Initialize = (NvAPI_Initialize_t) (*NvAPI_QueryInterface)(0x0150E828);
NvAPI_EnumPhysicalGPUs = (NvAPI_EnumPhysicalGPUs_t) (*NvAPI_QueryInterface)(0xE5AC921F);
NvAPI_GPU_GetUsages = (NvAPI_GPU_GetUsages_t) (*NvAPI_QueryInterface)(0x189A1FDF);
NvAPI_GPU_GetThermalSettings = (NvAPI_GPU_GetThermalSettings_t) (*NvAPI_QueryInterface)(0xE3640A56);
if (NvAPI_Initialize == NULL || NvAPI_EnumPhysicalGPUs == NULL ||
NvAPI_EnumPhysicalGPUs == NULL || NvAPI_GPU_GetUsages == NULL)
{
std::cerr << "Couldn't get functions in nvapi.dll" << std::endl;
return 2;
}
// initialize NvAPI library, call it once before calling any other NvAPI functions
(*NvAPI_Initialize)();
NV_GPU_THERMAL_SETTINGS nvgts;
int gpuCount = 0;
int gpuTemp;
int *gpuHandles[NVAPI_MAX_PHYSICAL_GPUS] = { NULL };
unsigned int gpuUsages[NVAPI_MAX_USAGES_PER_GPU] = { 0 };
// gpuUsages[0] must be this value, otherwise NvAPI_GPU_GetUsages won't work
gpuUsages[0] = (NVAPI_MAX_USAGES_PER_GPU * 4) | 0x10000;
(*NvAPI_EnumPhysicalGPUs)(gpuHandles, &gpuCount);
nvgts.version = sizeof(NV_GPU_THERMAL_SETTINGS) | (1<<16);
nvgts.count = 0;
nvgts.sensor[0].controller = -1;
nvgts.sensor[0].target = NVAPI_THERMAL_TARGET_GPU;
// print GPU usage every second
for (int i = 0; i < 100; i++)
{
(*NvAPI_GPU_GetThermalSettings)(gpuHandles[0], 0 ,&nvgts);
printf("%d\n", nvgts.sensor[0].currentTemp);
(*NvAPI_GPU_GetUsages)(gpuHandles[0], gpuUsages);
int usage = gpuUsages[3];
std::cout << "GPU Usage: " << usage << std::endl;
Sleep(1000);
}
return 0;
}
