This usually delivers outstanding frame rates, but memory size constraints can limit artistic creativity. Depending on the graphics card, texture space could be as low as only one megabyte or possibly as high as five or six megabytes. Use the OS to manage textures in main memory, and require the CPU to copy textures from main memory to graphics memory as needed. In order to make AGP look as good as possible, Intel likes to compare AGP to this mode. This is what DirectX Retained Mode does, but game developers do not generally use this method.
Performance is very good.
This has been the preferred approach for game developers, and can be programmed under Direct X Immediate Mode. AGP is a modified approach to option 3. Memory management is a little more flexible, and the data transfer rate is better because of AGP s faster clock speed and bus pipelining. AGP offers two ways to deal with textures. The other is Execute Mode, which allows the graphics chip to access the texture information in main memory without first copying it to graphics memory.