Run 2 Multiprocessors from one global function

Accelerated Computing CUDA CUDA Programming and Performance
1

When I run deviceQuery:

Device 0: "GeForce GT 730"
  CUDA Driver Version / Runtime Version          9.1 / 9.1
  CUDA Capability Major/Minor version number:    3.5
  Total amount of global memory:                 2002 MBytes (2099118080 bytes)
  ( 2) Multiprocessors, (192) CUDA Cores/MP:     384 CUDA Cores
  GPU Max Clock rate:                            1006 MHz (1.01 GHz)
  Memory Clock rate:                             2505 Mhz
  Memory Bus Width:                              64-bit
  L2 Cache Size:                                 524288 bytes
  Maximum Texture Dimension Size (x,y,z)         1D=(65536), 2D=(65536, 65536), 3D=(4096, 4096, 4096)
  Maximum Layered 1D Texture Size, (num) layers  1D=(16384), 2048 layers
  Maximum Layered 2D Texture Size, (num) layers  2D=(16384, 16384), 2048 layers
  Total amount of constant memory:               65536 bytes
  Total amount of shared memory per block:       49152 bytes
  Total number of registers available per block: 65536
  Warp size:                                     32
  Maximum number of threads per multiprocessor:  2048
  Maximum number of threads per block:           1024
  Max dimension size of a thread block (x,y,z): (1024, 1024, 64)
  Max dimension size of a grid size    (x,y,z): (2147483647, 65535, 65535)
  Maximum memory pitch:                          2147483647 bytes
  Texture alignment:                             512 bytes
  Concurrent copy and kernel execution:          Yes with 1 copy engine(s)
  Run time limit on kernels:                     Yes
  Integrated GPU sharing Host Memory:            No
  Support host page-locked memory mapping:       Yes
  Alignment requirement for Surfaces:            Yes
  Device has ECC support:                        Disabled
  Device supports Unified Addressing (UVA):      Yes
  Supports Cooperative Kernel Launch:            No
  Supports MultiDevice Co-op Kernel Launch:      No
  Device PCI Domain ID / Bus ID / location ID:   0 / 1 / 0
  Compute Mode:
     < Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) >

When I am trying to call the function:

dim3 grid(300, 300 , 1);
dim3 threads(1024, 1024, 1);
hashScan_cuda2<<< grid , threads>>>

the code dosnot work, But when I trying to run:

dim3 grid(300, 300 , 1);
dim3 threads(1024, 1, 1);
hashScan_cuda2<<< grid , threads>>>

The code runs well.
2) how can I run the:
Max dimension size of a thread block (x,y,z): (1024, 1024, 64)
Max dimension size of a grid size (x,y,z): (2147483647, 65535, 65535)

  1. And what is and how to do it?
    (multiple host threads can use ::cudaSetDevice() with device simultaneously)
2

The maximum dimension of a thread block gives the maximum for each axis individually,
but the total number of threads per block must not exceed another strict hardware limit:

Maximum number of threads per block: 1024

So this is illegal: dim3 threads(1024, 1024, 1);

3

So what does

Maximum number of threads per multiprocessor:  2048

this means?

4

that 2 blocks of maximum size can be resident (executed) on a multiprocessor at any given time