Basically, I have very poor 3D performance on everything OpenGL when using Unity3D. GLXGears gives me an average fps of 33FPS on Unity3D, while using Unity2D gives me an average of 58FPS. So, I was wondering if it's possible to load just Compiz and Unity3D using the llvmpipe software renderer, while still being able to have hardware accelerated OpenGL for everything else, to keep my FPS up, so I can play my games. My graphics hardware is an ATI RS480. I'm using the stock Ubuntu drivers with the extra DRI package installed, as I've found out that using Oibaf's Graphics PPA screws everything OpenGL up for and makes all of the games I play (urban terror, WINE games, OpenArena) not render correctly. In the case of WINE applications, they ALL crash.
LLVMpipe is an especially interesting Gallium3D driver since it allows accelerating the state trackers atop any modern CPU, but for any close to decent level of performance when using OpenGL you need a hefty multi-core CPU (here's some LLVMpipe benchmarks just from last week) that supports the latest SSE4 instructions as well. While some OpenGL games will run with LLVMpipe and the performance of this driver that leverages the Low-Level Virtual Machine is much faster and better than Mesa's old software rasterizer or the Gallium3D Softpipe driver, Compiz nor the GNOME Shell (and most other compositing window managers) yet work with this driver.
Sorry, but that means no.
which driver are you using? best idea seems to install your drivers with jockey. as far as i know llvmpipe isnt supported yet. i had heard rumors that it will be introduced in ubuntu 12.10. But i wont expect too much from llvmpipe. It is most likely that llvmpipe will be much slower than using the properity drivers.
As a curiosity, I did try compiling the Mesa LLVMpipe driver manually on a 12.04 install, then using it with Unity 3D via "UNITY_FORCE_START=1" and -- while the performance is pretty decent with LLVMpipe and a modern CPU in a game like Chromium, with Unity 3D a highend machine was slowed to a crawl, with compiz using 25% to 75% of a core @ about 1/2 fps, and gobbling up between 1 and 3 GB of RAM (which, when it peaked, started getting swapped out leaving the machine completely unresponsive).
In other words, it's a neat idea, but sadly not practical.