Originally Posted by Rubberman
That's not completely accurate. The DRM interface
'is a framework for allowing direct access to graphics hardware under the X Window System'. Now, that doesn't mean any userspace application can write willy-nilly to video memory or to other video hardware. However, under certain controlled circumstances, in concert with the right kernel module(s) and X libraries, X will orchestrate direct access to low-level video hardware. This should provide speeds that are comparable to any other graphics rendering of a similar category (ie. doesn't include advanced rendering capabilities like 3D computations, texture mapping, etc). Obviously, this applies at the X server end of the system, so rendering across a network is still limited by the network-related layers. But, X is efficient there, too. In many cases, a small command (in terms of message size) sent to an X server may result in significant work done by the server.