The status of Intel video drivers for Ubuntu

Corresponding changes were made to the Linux kernel, including migrating the new Graphics Execution Manager (GEM), which manages video memory, into the mainline kernel beginning with version 2.6.28. Setting graphics resolution, which has traditionally been done as part of the X server, has also been migrated to the kernel. Kernel Mode Setting (KMS) is now enabled by default in the most recent Ubuntu 9.10 alpha release.

The changes in both the Intel driver and the kernel also required changes to X.Org. Even my brief and decidedly less than detailed description of these changes makes it obvious that an awful lot of Linux core code has been undergoing some very major changes during the past year. Sadly, the results have, at least so far, meant that for many users of some of the most popular Linux distributions, performance did not improve. Quite the opposite: performance severely deteriorated and instability was introduced. Some users who upgraded their systems to the latest and greatest version of their favorite distribution found themselves with a system that ran very poorly, crashed frequently, or in some cases, found that X wouldn't work at all. Phoronix described their testing of Ubuntu 9.04 on a Samsung netbook this way: "...a buggy Intel Linux graphics stack led to slow performance, stability issues, screen corruption, and other problems."

I freely admit that I am not an expert on X.Org internals or graphics drivers but I've tried to follow the technical discussions, the issues involved, and how they have impacted Linux distributions. Today we'll look at the state of Intel graphics in several popular distributions, looking both at what went right and what went wrong in recent releases, what progress has been made, and what can be expected from upcoming releases.

Ubuntu 9.04 was released on April 23rd and users with Intel graphics were severely impacted. The Ubuntu forum includes a Jaunty Intel Graphics Performance Guide which offers three possible workarounds, all of which involve upgrading the Intel driver to a 2.7.x release and possibly upgrading the kernel as well. At the end of the guide are responses and reports from Ubuntu users totalling an amazing 107 pages. Glancing through the reports will reveal mixed results. For some users the problems they had experienced were completely resolved. Others reported no improvement. With my Intel Mobile Express 945GME graphics chipset the best I could achieve was either excellent performance but poor stability in the form of system freeze-ups or X crashes, or poor performance and some video corruption but excellent stability. Another workaround is to revert to an older 2.4.1 Intel driver, an approach which was abandoned early on in the forum but which worked reasonably well for me.

In the discussion which follows the Performance Guide, the Ubuntu developers make it clear they will not be porting more recent kernel builds or Intel drivers to 9.04. Development is now focused on solving the problems in time for the release of 9.10 on October 29th.

The third alpha of Ubuntu 9.10 shipped with the latest 2.8.0 Intel driver, X.Org Server 1.6.2 RC1, and a development snapshot of the Linux 2.6.31 kernel. Phoronix reported poor performance test results with this alpha but I found significant improvement on my system. Ubuntu 9.10 alpha 4, released last week, also includes a newer kernel snapshot and the 2.8.0 driver, which no longer supports EXA and DRI1. While enabling UXA and DRI2 caused instability on my system with the 2.7.x drivers I have no such problem with 2.8.0. With 3D animation enabled I do still see some brief video corruption for a second, perhaps less, when a new window is opened, and a corresponding stutter in whatever action is being performed. I wonder if the stutter I see is part of the cause of the poor performance numbers the Phoronix testers saw. Once a window is open performance seems to be very good. I see no problems at all with 2D graphics using the latest Ubuntu 9.10 build. This is the same result I reported in my review of Pardus 2009 last week. Even though this is an early alpha build with some bugs I found Ubuntu 9.10 to already be far more usable than Ubuntu 9.04.

I should mention that Ubuntu 8.04 LTS uses older code and was not affected. Ubuntu Netbook Remix 8.04 was the factory installed OS on my netbook. With all the latest updates it performs flawlessly.

source : distrowatch