CUFFT中FFT点数对FFT性能的影响测试

基2FFT比非基2FFT的运行速度要快，在NVIDIA GPU设备上使用FFT的时候也是尽量使用基2FFT，因为本身使用GPU就是为了追求快速计算。测试了下一个二维复数矩阵在基2FFT和非基2FFT的性能差别（二维矩阵中的一个维度进行FFT，用到了batch）。从我测试的结果来看，基2FFT比非基2FFT快5倍。测试的数据尺寸：基2FFT：512×16384，非基2FFT：428×16384，测试数据是用matlab生成的。

 %生成用于cufft测试的随机数（使用matlab生成的，也可以在GPU程序中生成）
 close all;
 clear; clc;
 a1 = randn(428 * 2, 1);         %生成428点长度的随机数, 复数据，按IQ存储
 a2 = zeros(428 * 2, 16384);
 for ii = 1 : 16384,
     a2(:, ii) = a1;
 end,
 clear a1;
 b1 = randn(512 * 2, 1);
 b2 = zeros(512 * 2, 16384);
 for ii = 1 : 16384,
     b2(:, ii) = b1;
 end,
 clear b1;
 %将生成的随机数写到硬盘，以用于c程序调用
 output_file_428='D:/cufft_test/428.dat';
 output_file_512='D:/cufft_test/512.dat';
 fid1 = fopen(output_file_428, 'w');
 fid2 = fopen(output_file_512, 'w');
 fwrite(fid1, a2, 'single');
 fwrite(fid2, b2, 'single');
 fclose(fid1);
 fclose(fid2);

 

GPU测试程序：

 #include
 #include
 #include
 #include
 #include
 #include
 #include           //使用openmp开启了CPU并行
 using namespace std;
 //设备端头文件
 #include
 #include
 typedef float2 Complex;             //复数类型
 #define datasize_428 7012352
 #define datasize_512 8388608
 char data_file_428[200] = "D://cufft_test//428.dat";
 char data_file_512[200] = "D://cufft_test//512.dat";
 int main(int argc, char* argv[])
 {
     clock_t start, end, start1, end1, start2, end2;
     time_t timer;
     struct tm *tblock;
     /* gets time of day */
     timer = time(NULL);
     /* converts date/time to a structure */
     tblock = localtime(&timer);
     start = clock();
     system("cls");
     system("color 0a");
     printf("Local time:  %s",  asctime(tblock));
     cudaSetDevice(cutGetMaxGflopsDeviceId());
     int devID;
     cudaDeviceProp props;
     //get number of SMs on this GPU
     cutilSafeCall(cudaGetDevice(&devID));
     cutilSafeCall(cudaGetDeviceProperties(&props, devID));
     printf("Device %d: /"%s/" with Compute %d.%d capability/n", devID, props.name, props.major, props.minor);
     cudaSetDevice(cutGetMaxGflopsDeviceId());
     //读取428点的测试数据
     Complex *echodata_428 = new Complex[datasize_428];              //存放回波复数据
     float *echo_iq_428 = new float[2 * datasize_428];               //用于读取存在硬盘上的IQ回波
     FILE *fp_echo_428;
     int ncount = 0;             //用于数据校验
     printf("Now start to read float type echo data from disk/n");
     fp_echo_428 = fopen(data_file_428, "rb");
     if (fp_echo_428 == NULL)
     {
         printf("Open echo data file fails!/n");
     }
     else
     {
         ncount = fread(echo_iq_428, sizeof(float), 2 * datasize_428, fp_echo_428);
         if (ncount != 2 * datasize_428)
         {
             printf("Read data from disk error, not completely!/n");
         }
         else
         {
             printf("Read echo data sucesses/n");
             fclose(fp_echo_428);
         }
     }
     printf("now, start to transform the [I Q] data to complex type/n");
     int i;
 #pragma omp parallel for num_threads(8) private(i)
     for (i = 0; i < datasize_428; i++)
     {
         echodata_428[i].x = echo_iq_428[2 * i];
         echodata_428[i].y = echo_iq_428[2 * i + 1];
     }
 #pragma omp barrier
     /*free(echo_iq);
     echo_iq = NULL;*/
     printf("transform the [I Q] echo data to complex type successes/n");
     //读取512点的测试数据
     Complex *echodata_512 = new Complex[datasize_512];              //存放回波复数据
     float *echo_iq_512 = new float[2 * datasize_512];               //用于读取存在硬盘上的IQ回波
     FILE *fp_echo_512;
     ncount = 0;             //用于数据校验
     printf("Now start to read float type echo data from disk/n");
     fp_echo_512 = fopen(data_file_512, "rb");
     if (fp_echo_512 == NULL)
     {
         printf("Open echo data file fails!/n");
     }
     else
     {
         ncount = fread(echo_iq_512, sizeof(float), 2 * datasize_512, fp_echo_512);
         if (ncount != 2 * datasize_512)
         {
             printf("Read data from disk error, not completely!/n");
         }
         else
         {
             printf("Read echo data sucesses/n");
             fclose(fp_echo_512);
         }
     }
     printf("now, start to transform the [I Q] data to complex type/n");
 #pragma omp parallel for num_threads(8) private(i)
     for (i = 0; i < datasize_512; i++)
     {
         echodata_512[i].x = echo_iq_512[2 * i];
         echodata_512[i].y = echo_iq_512[2 * i + 1];
     }
 #pragma omp barrier
     /*free(echo_iq);
     echo_iq = NULL;*/
     printf("transform the [I Q] echo data to complex type successes/n");

     //428点傅里叶变换
     start1 = clock();
     printf("start to do 428 points fft/n");
     Complex *g_idata_428_fft;
     cufftHandle plan_428;               //创建CUFFT句柄
     //在GPU上为信号开辟空间
     cutilSafeCall(cudaMalloc((void **)&g_idata_428_fft, datasize_428 * 8));
     //将开辟的显存全部置零
     cutilSafeCall(cudaMemset((void *)g_idata_428_fft, '/0', datasize_428 * 8));
     //拷贝内存信号到显存
     cutilSafeCall(cudaMemcpy(g_idata_428_fft, echodata_428, datasize_428 * 8, cudaMemcpyHostToDevice));
     //start1 = clock();
     cufftSafeCall(cufftPlan1d(&plan_428, 428, CUFFT_C2C, 16384));
     cufftSafeCall(cufftExecC2C(plan_428, (cufftComplex *)g_idata_428_fft, (Complex *)g_idata_428_fft, CUFFT_FORWARD));
     end1= clock();
     //拷贝显存数据到内存
     cutilSafeCall(cudaMemcpy(echodata_428, g_idata_428_fft, datasize_428 * 8, cudaMemcpyDeviceToHost));
     cufftSafeCall(cufftDestroy(plan_428));
     cutilSafeCall(cudaFree(g_idata_428_fft));
     printf("428 points fft finishes/n");

     //512点傅里叶变换
     start2 = clock();
     printf("start to do 512 points fft/n");
     Complex *g_idata_512_fft;
     cufftHandle plan_512;               //创建CUFFT句柄
     //在GPU上为信号开辟空间
     cutilSafeCall(cudaMalloc((void **)&g_idata_512_fft, datasize_512 * 8));
     //将开辟的显存全部置零
     cutilSafeCall(cudaMemset((void *)g_idata_512_fft, '/0', datasize_512 * 8));
     //拷贝内存信号到显存
     cutilSafeCall(cudaMemcpy(g_idata_512_fft, echodata_512, datasize_512 * 8, cudaMemcpyHostToDevice));
     //start2 = clock();
     cufftSafeCall(cufftPlan1d(&plan_512, 512, CUFFT_C2C, 16384));
     cufftSafeCall(cufftExecC2C(plan_512, (cufftComplex *)g_idata_512_fft, (Complex *)g_idata_512_fft, CUFFT_FORWARD));
     end2 = clock();
     //拷贝显存数据到内存
     cutilSafeCall(cudaMemcpy(echodata_512, g_idata_512_fft, datasize_512 * 8, cudaMemcpyDeviceToHost));
     cufftSafeCall(cufftDestroy(plan_512));
     cutilSafeCall(cudaFree(g_idata_512_fft));
     printf("512 points fft finishes/n");
     end = clock();
     double duration = double(end - start)/ CLOCKS_PER_SEC;
     printf("This Tool uses %f s/n", duration);
     double duration1 = double(end1 - start1)/ CLOCKS_PER_SEC;
     printf("428 points fft uses %f s/n", duration1);
     double duration2 = double(end2 - start2)/ CLOCKS_PER_SEC;
     printf("512 points fft uses %f s/n", duration2);
     getchar();
     return 0;
 }