マルチコアCPUとGPUを併用した並列計算 / Parallel computing combined use of multi-core CPU and multi-GPU

以下のプログラムをマルチコアCPUとGPUを併用して並列計算をしたいのですが、parpoolで並列プールを呼び出しても、マルチコアCPU物理コア数のみしか呼び出せません。どのように設定すればGPUを併用した並列計算をできるのでしょうか？

I would like to perform parallel computation of the following program by combined use of multi-core CPU and multi-GPU, but when I call the parpool('local'), MATLAB can only be called the multi-core CPU. How should I set it up so that I can do the parallel calculation by combined use of multi-core CPU and multi-GPU?

n = 10000;
m = 500;
v = zeros(1,n);

parpool('local');

parfor i=1:n
A = rand(1,m);
B = rand(m,1);

v(i) = A*B;
end

delete(gcp('nocreate'));

[Masanari DATEKYU]

過去の質問から、以下のプログラムを実行 / From past questions, run the following program

n = 1000;
m = 500;
v = zeros(1,n);

parpool('local');

tic;
parfor i=1:n
    if mod(i,16)==0
        gpuDevice(1);
        A = rand(1,m,'gpuArray');
        B = rand(m,1,'gpuArray');
        v(i) = A*B;
    elseif mod(i,16)==1
        gpuDevice(2);
        A = rand(1,m,'gpuArray');
        B = rand(m,1,'gpuArray');
        v(i) = A*B;
    elseif mod(i,16)==2
        gpuDevice(3);
        A = rand(1,m,'gpuArray');
        B = rand(m,1,'gpuArray');
        v(i) = A*B;
    elseif mod(i,16)==3
        gpuDevice(4);
        A = rand(1,m,'gpuArray');
        B = rand(m,1,'gpuArray');
        v(i) = A*B; 
    else
        A = rand(1,m);
        B = rand(m,1);
        v(i) = A*B;
    end
end
toc

delete(gcp('nocreate'));

Result：CPU → 0.39sec、CPU＋GPU→50sec

GPU使用量が増えたためGPU並列計算が可能となったが、何故か実行時間がCPUよりも劇的に増えた。

Parallel computation by combined use of multi-core CPU and multi-GPU can be done because of the increased GPU usage, but processing time of CPU+GPU is more dramatically long than the only multi-core CPU