CODEWITHSUNDEEP
c++openglmemory-managementglsl
Irbis
Irbis

Reputation: 13509

OpenGL - gpu memory exceeded, possible scenarios

I can use glTexImage2D or glBufferData to send some data to the gpu memory. Let's assume that I request driver to send more data to the gpu but the gpu memory is already full. I probably get GL_OUT_OF_MEMORY. What might happen with a rendering thread ? What are possible scenarios ? Is it possible that a rendering thread will be terminated ?

Upvotes: 0

Views: 1947

Answers (1)

datenwolf
datenwolf

Reputation: 162297

It depends on the actual OpenGL implementation. But the most likely scenario is, that you'll just encounter a serious performance drop, but things will just keep working.

OpenGL uses an abstract memory model, for which actual implementation threat the GPU's own memory as a cache. In fact for most OpenGL implementation when you load texture data it doesn't even go directly to the GPU at first. Only when it's actually required for rendering it gets loaded into the GPU RAM. If there are more textures in use than fit into GPU RAM, textures are swapped in and out from GPU RAM as needed to complete the rendering.

Older GPU generations required for a texture to completely fit into their RAM. The GPUs that came out after 2012 actually can access texture subsets from host memory as required thereby lifting that limit. In fact you're sooner running into maximum texture dimension limits, rather than memory limits (BT;DT).

Of course other, less well developed OpenGL implementations may bail out with an out of memory error. But at least for AMD and NVidia that's not an issue.

Upvotes: 1

Related Questions