Intel Sandy Bridge Linux Graphics? It's A Challenge
Last month I already wrote at length about the support status of Intel Sandy Bridge in terms of its new chipsets and the CPUs. To summarize that, the support should be in place aside from LM_Sensors potentially not working with some of the new H67/P67 motherboards and to utilize the next-generation Intel graphics you will need to jump over some hurdles at this time. While we can easily jump those hurdles, not everyone can and it's a hassle for many Linux users. Intel decided not to send out any Sandy Bridge CPU samples to us, so we are unable to deliver test results, but all I got were frustrated journalists asking me how to get the Sandy Bridge graphics working under Linux. So that they could then run the Phoronix Test Suite.
As I've been saying, Ubuntu 10.10 will not work fully with the Sandy Bridge CPU's graphics as its stack is too old. Intel has been working on Sandy Bridge open-source Linux support going back a year now, and some of the DRM and DDX bits have been living in mainline trees for months, but it's not the polished and proper support. For the proper Sandy Bridge experience you are left looking for the Linux 2.6.37 kernel, Mesa 7.10, the latest libdrm, and the xf86-video-intel 2.14.0 DDX that should be released in the next week or so. If you are trying to use MPEG2 / H.264 VA-API video acceleration, you will also need to be pulling libva (the VA-API library) from Git as the Sandy Bridge support upbringing is in no official release either.
With Ubuntu 10.10 you may get kernel mode-setting so your display will at least light up and you can use your desktop, but no Compiz, no 3D acceleration, no VA-API. To get all of this you will need to pull those five mentioned components (Linux kernel, Mesa, libdrm, xf86-video-intel, and libva [optionally for video acceleration]) from source or their tar-balls once they are officially released. These will not appear in Ubuntu 10.10 updates repository or anywhere else until Ubuntu 11.04 is released. If you're lucky there will be a PPA / third-party repository with some of these bits, but nothing official.
Intel does have out launch-day support (in the form of Git code) for the new graphics found on Sandy Bridge, but you must be willing and comfortable building the graphics stack from source on any modern Linux distribution. This would be a big problem for new Linux users and even journalists -- aside from at Phoronix where building graphics drivers from source is a daily ritual. Unfortunately, the open-source Linux graphics driver stack does not allow new/updated drivers to be easily installed like driver installations are done on Windows or under Linux with the ATI Catalyst and NVIDIA binary drivers.
Charlie Demerjian at SemiAccurate has written a very scathing review against Sandy Bridge for this very reason: Sandy Bridge is the biggest disappointment of the year. Charlie feels that Sandy Bridge is a broken platform since there aren't Linux drivers working "out of the box" on Ubuntu 10.10. "The down side is pretty painful. Intel offers a bunch of must have, make your life better, brings world peace, flowers, and the like level features on Sandy Bridge. The working count on Linux? Zero on launch. The chance that they will ever work on Linux? Just slightly above zero, think the need for extended floating point precision to see that many zeros...So, back to the 'must have or your coffee shop experience is not complete' feature set. They include Video Processing Accelerators - never coming to Linux, Color Processing Accelerators - never coming to Linux, Skin Tone Enhancements - never coming to Linux, Adaptive Contrast Enhancement - never coming to Linux, Total Color Control - never coming to Linux, Video Decode in hardware - Q1, Video Encode in hardware - Q1, 3D acceleration - Q1 sooner rather than later and a host of software to use it - never coming to Linux."
Due to the lack of drivers out of the box, he even compares the Sandy Bridge performance using the Mesa Software Rasterizer. Obviously the Mesa Software Rasterizer is bloody horrific, but it would have been possible and interesting to see Sandy Bridge running with the LLVMpipe driver to see how well that LLVM-based software pipeline works on this new Intel micro-architecture, but we'll have to wait until we can get our hands on the hardware to be able to run some competent Linux tests.
Charlie though isn't the only early Sandy Bridge Linux user facing these problems. One of my fellow Augustiner-drinking journalists from Munich was also facing problems. "No beef so far in getting the GPU to w0k under Linux, but I didn't expect it would... Did you hear anything about support? I did ask Intel but no beef so far!"
After explaining things to him about needing the latest Git components at the time in mid-December, "Building what from git? <:-) The kernel? X? DRM? I gotta say I tried building my own ubuntu kernel from current sources once back when Clarkdale came out with its GMA HD gfx, and it was a horrible, horrible mess, I got it *barely* to work, and the system was completely messed up afterwards, I was unable to revert back to a proper Ubuntu install.."
Rather than playing in the land of dependencies and code compiling, he tried out an Ubuntu 11.04 daily snapshot, but even in December the bits hadn't landed. "No go on Natty, just tried it. It tells me I have no 3D graphics.. gfxinfo confirms this, mesa-software rasterizer, just like in 10.10..."
The other funny thing about the situation is that if we had Sandy Bridge access we could have easily spun a new release of PTS Desktop Live, our own Linux-based operating system designed for standardized benchmarking with the Phoronix Test Suite, with these latest Git components so that there would have been a reliable platform for these other journalists and early adopters. Down the road what I see happening from this situation and others like it is Intel's PR department beginning to offer up PPAs or going as far as spinning their own Ubuntu or Fedora remix to incorporate these bleeding-edge components. On the Windows side they already offer up "performance evaluation guides" and the like, along with press drivers, (as does nearly every major hardware vendor) but the package repositories / spin-a-remix is what they would have to do to make it easy for early Linux testers to ensure they write about a pleasant Linux experience for their hardware.
So long story short, while you probably will be hard-pressed to find any Linux graphics benchmark results today for Sandy Bridge, there are Linux drivers available. They though are not for the faint-hearted Linux user as if purchasing this hardware before the spring roll-out of Ubuntu 11.04, Fedora 15, etc it will not be an "out of the box" experience but rather fetching packages from source or third-party repositories and hoping everything plays together well. This is like usual for Intel, but the Linux user's expectation has gone from wanting drivers at time of launch to wanting drivers working "out of the box" on the distribution of their choice at time of launch.
Aside from that though, you shouldn't hit any other major Linux snags in the process. As soon as we buy (feel free to help by subscribing to Phoronix Premium or using our NewEgg / Amazon shopping links) or are able to get our hands on the new Core i3/i5/i7 processors we, of course, will be delivering Linux benchmarks on the graphics side and of the CPU itself with our industry-leading Phoronix Test Suite. Let's just hope though that when we build the latest Git code, that everything performs well and that the OpenGL performance on Sandy Bridge is nice with Intel still using a classic Mesa DRI driver rather than moving to the Gallium3D architecture.
One interesting thing that has emerged though is that this quarter (Q1'2011), Intel will evidently be enabling Sandy Bridge video encoding support under Linux too. Not only is there video decoding support right now for Sandy Bridge if using the latest Git of libva and the Intel DRM (Direct Rendering Manager), but encoding support is said to be coming too. This would be pleasant to see and should be possible to be exposed over the VA-API interface as well. Though these bits will likely not be in Ubuntu 11.04, Fedora 15, etc so good luck to the other reviewers or any light-hearted Linux users in getting the video encode bits to work.
In 2011, Linux hardware support continues to be a challenge, but it's getting better and is in far better shape than when Phoronix launched seven years ago. The Sandy Bridge launch for Linux is arguably even better than the Arrandale / Clarkdale launch as there you had to wait months after launch for the H.264 VA-API support.
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