GPU Memory Model Overview

Buffers:

• 1. Color Buffer

     1. Front left

     2. Front right

     3. Back left

     4. Back right

  2. Depth Buffer

  3. Stencil Buffer

  4. Accumulation Buffer

CPU and GPU Memory Hierarchy

CPU Memory Model

• 1. At any program point Allocate/free local or global memory

  2. Random memory access

     1. Registers

        1. Read/write

     2. Local memory

• • • 1. Read/write to stack

• 2. 3. Global memory

• • • 1. Read/write to heap

• 2. 4. Disk

• • • 1. Read/write to disk

GPU Memory Model

Much more restricted memory access

• 1. Allocate/free memory only before computation

  2. Limited memory access during computation (kernel)

     1. Registers

        1. Read/write

     2. Local memory

• • • 1. Read/write

• 2. 3. Shared Memory

• • • 1. Only available in GPGPU not Graphics pipeline

• 2. 4. Global memory

• • • 1. Read-only during computation

      2. Write-only at end of computation (pre-computed address)

      3. Read/write in GPGPU world only

• 2. 5. Virtual Memory

• • • 1. Does not exist

• 2. 6. Disk access

• • • 1. Does not exist

Where is GPU Data Stored?

• 1. Vertex buffer

  2. Frame buffer

  3. Texture