cuda - cudaMallocManaged() returns "operation not supported" -

trying out managed memory in cuda 6.0 gives me operation not supported when calling cudamallocmanaged().

#include "cuda_runtime.h"  #include <stdio.h>  #define check(r) {_check((r), __line__);}  void _check(cudaerror_t r, int line) {   if (r != cudasuccess) {     printf("cuda error on line %d: %s\n", line, cudageterrorstring(r), line);     exit(0);   } }  int main() {   int *c;   check(cudamallocmanaged(&c, sizeof(int)));   *c = 0;   return 0; } 

geforce gtx 750 ti (maxwell), compiled cuda 6.0 using compute_50,sm_50. windows 7 64-bit. tested drivers 335.23 (whql) , 337.50 (beta). visual studio 2012. tried 32-bit debug , release builds.

c:\rd\projects\cpp\test_cuda6\test_cuda6>"c:\program files\nvidia gpu computing toolkit\cuda\v6.0\bin\nvcc.exe" -gencode=arch=compute_50,code=\"sm_50,compute_50\" --use-local-env --cl-version 2012 -ccbin "c:\program files (x86)\microsoft visual studio 11.0\vc\bin" -i\c\common\inc -i"c:\program files\nvidia gpu computing toolkit\cuda\v6.0\include" -i"c:\program files\nvidia gpu computing toolkit\cuda\v6.0\include" --keep-dir release -maxrregcount=0 --machine 32 --compile -cudart static -dwin32 -dndebug -d_console -d_mbcs -xcompiler "/ehsc /w3 /nologo /o2 /zi /md " -o release\kernel.cu.obj "c:\rd\projects\cpp\test_cuda6\test_cuda6\kernel.cu"

the program runs without error if replace cudamallocmanaged() cudamalloc().

any ideas on how cudamallocmanaged() working?

tried 32-bit debug , release builds.

use 64 bit debug or release build.

from the documentation:

j.1.4. system requirements

unified memory has 3 basic requirements:

•a gpu sm architecture 3.0 or higher (kepler class or newer)

•a 64-bit host application , operating system, except on android

•linux or windows

64 bit host application means cannot compile 32 bit debug or release build.