OSX 10.10 texture array upload performance

textureuploadperf.cpp

// Format 83f1: time to upload: 37.6 msec (1134.9 Mb/sec)
// Format 83f2: time to upload: 2109.5 msec (40.5 Mb/sec)
// Format 83f3: time to upload: 1984.0 msec (43.0 Mb/sec)
// Format 8dbb: time to upload: 22.7 msec (1876.9 Mb/sec)
// Format 8dbd: time to upload: 1942.0 msec (43.9 Mb/sec)

#include <sys/time.h>
#include <OpenGL/gl3ext.h>

double timestamp()
{
    struct timeval tv;
    if (gettimeofday(&tv, 0) == 0)
        return tv.tv_sec + tv.tv_usec * 1e-6;
    else
        return 0;
}

void testTextureUploadPerf()
{
    static char dummydata[1024*1024];
    
    GLenum formats[] =
    {
        GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
        GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,
        GL_COMPRESSED_RGBA_S3TC_DXT5_EXT,
        GL_COMPRESSED_RED_RGTC1,
        GL_COMPRESSED_RG_RGTC2,
    };
    
    for (unsigned int f = 0; f < sizeof(formats) / sizeof(formats[0]); ++f)
    {
        GLenum format = formats[f];
        
        double start = timestamp();
        
        GLuint texid;
        glGenTextures(1, &texid);
        glBindTexture(GL_TEXTURE_2D_ARRAY, texid);
        glTexStorage3D(GL_TEXTURE_2D_ARRAY, 11, format, 1024, 1024, 64);
        
        unsigned int total = 0;
        
        for (int z = 0; z < 64; ++z)
        {
            for (int mip = 0; mip < 11; ++mip)
            {
                int mipd = 1024 >> mip;
                int mipbits = (format == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT || format == GL_COMPRESSED_RED_RGTC1) ? 8 : 16;
                int mipsize = ((mipd + 3) / 4) * ((mipd + 3) / 4) * mipbits;
                
                glCompressedTexSubImage3D(GL_TEXTURE_2D_ARRAY, mip, 0, 0, z, mipd, mipd, 1, format, mipsize, dummydata);
            
                total += mipsize;
            }
        }
        
        glDeleteTextures(1, &texid);
        
        double end = timestamp();

        printf("Format %x: time to upload: %.1f msec (%.1f Mb/sec)\n", format, (end - start) * 1000.0, (double)total / (end - start) / 1048576);
    }
}