Does A Greedy Intel Driver Improve Performance?
Phoronix: Does A Greedy Intel Driver Improve Performance?
As we have outlined before and shared benchmarks of in the past, the Intel graphics driver stack has been going through some significant changes. The Intel graphics driver now has a proper memory manager in the form of the Graphics Execution Manager, there is upstream kernel mode-setting support, and a new 3D component is coming soon in the form of Gallium3D. With all of this invasive work going on, regressions are currently prevalent from stability problems to graphical corruption to slower 2D performance. While these are problems users will face with the new distribution updates in H1'09, some have been trying out different driver configurations in order to circumvent the situation. Canonical, for example, had been toying with the idea of enabling greedy migration heuristics by default.
There is xf86-video-intel 2.7 around a corner (currently 22.214.171.1243), so why didn't you test performance using that version?
Ubuntu 9.04 is shipping with 2.6 series. And 2.6.3 is still the latest *stable* release.
Originally Posted by Zajec
If I had an Intel based IGP, I really wouldn't know what to use.
It's a shame that you only tested one, 4 year old, chipset. (support for different chips is at different states, so this really means nothing to users of 950,965(that's me),4500 and a few others)
What does "greedy" actually mean? What changes this option in the driver? thx
I assume it comes from the term "greedy algorithm" which uses a heuristic to "guess" what is going to be the optimal path through a series of options. google it for more info.
Originally Posted by bugmenot
Looks like going with the older driver is the most sensible thing to do.
Of course, there will be a loud 20% who'll want the other 80% to play guinea pigs :|
Thanks for running these tests Michael.
For arm-chairing -intel integration strategy, also keep in mind performance is just one parameter. Stability can be an even more important concern (ruling out UXA), as is providing the latest support for newest chips (which makes 2.4 a less useful option).
Also, performance can vary from chip to chip, so while it is very nice having solid quantitative facts to judge from, they may differ noticeably on other intel hardware.
Fwiw, on my laptop (a Dell 1420 w/ i965 gfx), the "greedy" option has the effect of turning the compiz border shadows black and slowing the performance down severely. So YMMV.
I would be very interested in hearing from others who experience problems running with "greedy" enabled, to help inform our decision.