I am very new to OpenGL and can not quite wrap my mind around the concept of persistently mapped buffers.
The Memory resides on the GPU right? The pointer I get is to some sort of special memory, that gets transferred over the bus without touching client side memory? How is this technique called?
Is the transfer completely asynchronous and can the GPU work on different matter while data is transferred?
If I use the COHERENT flag will it sync for most gl calls and buffer reads? Is it just for the lazy programmer or is there a benefit to it I can not achieve by syncing manually?
Is this only possible on newer Hardware? I have looked for a database that shows which extensions are supported by which hardware. buffer_storage only showed some of the newer gpus.