• Locked Locked
  • Replies 3 replies
  • Subscribers 136 subscribers
  • Views 7073 views
  • Users 0 members are here
Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Mali 400 - Video memory available

Jean-Georges Levieux
Note: This was originally posted on 6th September 2012 at http://forums.arm.com

Hello,

We are developping a 3D game on a platform that has a Mali-400 MP4. I have a question about the video memory really available: the global chip has about 1go of memory (we can do 11 new of 100Mb each before to get a NULL pointer) but the memory available for graphics data seems quite low. Here is the code we used to check the available memory for both texture and VBO (tested seperatly):

// Vbo memory test.
    while (CheckGLError("Flush before VBO") == true); // Flush all previous errors.
    int const nSizeVBuffer = 512*1024;
    static char pDataVBuffer[nSizeVBuffer];
    int nNbVBO = 0;
    do
    {
        GLuint nVBufferID = 0;
        glGenBuffers( 1, &nVBufferID );
        glBindBuffer( GL_ARRAY_BUFFER, nVBufferID);
        glBufferData( GL_ARRAY_BUFFER, nSizeVBuffer, pDataVBuffer, GL_STATIC_DRAW);

        nNbVBO++;
        CPrintf::AddTextFile("Generate VBO %d (%d)\n", nNbVBO, nVBufferID);
    } while (CheckGLError("VBO Loading") == false);

// Here we "transfer" about only 70Mbytes before the GLerror.

// Texture memory test.
    while (CheckGLError("flush before Textures") == true); // Flush all previous errors.
    int const nW = 256;
    int const nH = 256;

    static char pTabPixel[nW * nH * 4];
    int nNbTexLoaded = 0;
    do
    {
        GLuint nTexId;

        glGenTextures ( 1, &nTexId);
        glBindTexture ( GL_TEXTURE_2D, nTexId);

        CPrintf::AddTextFile("Generate texture %d (%d)\n", nNbTexLoaded, nTexId);

        glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGB, nW, nH, 0, GL_RGB, GL_UNSIGNED_BYTE, pTabPixel);

        nNbTexLoaded++;

    } while (CheckGLError("Texture loading") == false);

// Here we "transfer" about only 90Mbytes before the GLerror.

So, in the best case it seems we have less than 100Mb of memory available for texture, vbo and ibo.

Does it seems a "normal" behavior or do we miss something? Could it be specific to the platform we are developping on (don't ask which one I cannot say)? Is there any way to have more "graphic" memory on Mali GPU?

Thank you in advance for your answers....

Regards,




Parents
  • Note: This was originally posted on 6th September 2012 at http://forums.arm.com

    Hi Jgl,

    Thanks for your question. In platforms where the Mali400 GPU is using main memory, the maximum amount of memory available to it is set as a parameter when building the kernel driver, and so is platform/build specific.

    Are you building the driver yourself, either externally or as part of the kernel build? If so I can give direction on how to increase the amount of memory available to the GPU.

    Thanks
    Chris
Reply
  • Note: This was originally posted on 6th September 2012 at http://forums.arm.com

    Hi Jgl,

    Thanks for your question. In platforms where the Mali400 GPU is using main memory, the maximum amount of memory available to it is set as a parameter when building the kernel driver, and so is platform/build specific.

    Are you building the driver yourself, either externally or as part of the kernel build? If so I can give direction on how to increase the amount of memory available to the GPU.

    Thanks
    Chris
Children
No data