Intel Sandy Bridge Linux Graphics? It's A Challenge

[popper]

It is not a "programming error". It is a hardware limitation.

well i did put a there ;D
but still... is it a case of a control 'bit' being set/unset on or off wrongly, or a 'real hardware errata' that they know about and have not fixed, did anyone bother to report this known error on [email protected] for instance ?

[smitty3268]

I don't guess there are any workarounds other than an extra frame every 40* seconds?

* (24 frames/sec - 23.976 frames/sec) * 40 sec = ~1 frame.

According to that Anandtech article, Intel did come up with a workaround in their drivers that can change the framerate to 23.970. That comes out to 1 frame every 160 seconds.

[popper]

To be clear, a hardware problem that has existed since Clarkdale is preventing accelerated playback of 23.97 FPS video without stuttering on Sandy Bridge's graphics?

which strikes me as odd, given that Clarkdale uses a dual-core Westmere and sticks it next to the 45nm Intel GMA die, where as Sandy bridge is totally new and in the core and uses the new rings tied the the L3.

that implies program error somewhere not hardware errata, someone should perhaps ask for clarity and post a test case to prove it on [email protected] as we are just assuming right now it seems!

[smitty3268]

which strikes me as odd, given that Clarkdale uses a dual-core Westmere and sticks it next to the 45nm Intel GMA die, where as Sandy bridge is totally new and in the core and uses the new rings tied the the L3.

that implies program error somewhere not hardware errata, someone should perhaps ask for clarity and post a test case to prove it on [email protected] as we are just assuming right now it seems!

From Anandtech, it's a hardware problem that Intel knows about.

The limitation is entirely in hardware, particularly in what?s supported by the 5-series PCH (remember that display output is routed from the processor?s GPU to the video outputs via the PCH). One side effect of trying to maintain Intel?s aggressive tick-tock release cadence is there?s a lot of design reuse. While Sandy Bridge was a significant architectural redesign, the risk was mitigated by reusing much of the 5-series PCH design. As a result, the hardware limitation that prevented a 23.976Hz refresh rate made its way into the 6-series PCH before Intel discovered the root cause.

Intel had enough time to go in and fix the problem in the 6-series chipsets, however doing so would put the chipset schedule at risk given that fixing the problem requires a non-trivial amount of work to correct. Not wanting to introduce more risk into an already risky project (brand new out of order architecture, first on-die GPU, new GPU architecture, first integrated PLL), Intel chose to not address it this round, which is why we still have the problem today.

[gbeauche]

Correct me if I'm wrong but IIRC Media Espresso doesn't actually do the actual encoding on the GPU, that is still done on the CPU. What is done on the GPU is the filtering, resizing etc the same as TMPEnc does.

They have a special version that enables HW decode & encode on Intel Sandy Bridge. Likewise, the CUDA version uses the new NVIDIA component. Hence, quality is not that good.

Some tests:

http://www.anandtech.com/show/4083/the-sandy-bridge-review-intel-core-i7-2600k-i5-2500k-core-i3-2100-tested/9#

http://www.legitreviews.com/article/1506/8/

http://static.pcinpact.com/images/bd/news/93176-sandy-bridge---mediaespresso-6.jpg

[gbeauche]

Phoronix: Intel Sandy Bridge Linux Graphics? It's A Challenge

This week at the Consumer Electronics Show in Las Vegas (I'll be there looking out for Linux), Intel will officially launch their next-generation Sandy Bridge micro-architecture and CPUs. The NDA though expired at midnight on these first CPUs so there is now a stream of reviews coming out. Is there any Linux graphics test results for the Core i5 2500K and Core i7 2600K? Unfortunately, there is not...

http://www.phoronix.com/vr.php?view=ODk2OA

libva 1.0.7 was released yesterday with Sandy Bridge bits in.

[Kano]

Yes, the code was not changed however since last year. When will you update your libva?

[Xwang]

I wonder if in the future it will be possible to buy a laptop with only a sandy bridge cpu (with integrated HD3000) and none discrete GPU and play to open source and Wine games.
Is the 3D acceleration already in the kernel driver?
Thank you,
Xwang

[Kano]

I don't think that it will be a good gameing cpu. It is restricted to opengl 2.1 most likely on Linux. Usually win drivers are much faster for games (dx10 support would be opengl 3.x hardware). Libva support seems more interesting for Linux users, but those cpus are really powerfull too now...

[OldYogi]

Nvidia as An Interim Solution?

A $30 dollar graphics card is a small price to pay.

I was planning to build a new machine for video editing (no games). All my machines are dual boot - Windows and Linux. The video editing will be done in Win 7. Am I correct that if I use the NVidia card from my old machine then even under Ubuntu the graphics with Sandy Bridge (e.g. Core i5 2500K) should be fine, and otherwise the Sandy Bridge cpu will function properly under both Win 7 and Ubuntu? Once Ubuntu learns to work with Sandy Bridge shouldn't I be able to remove the old NVidia card, and use the integrated HD 3000 ?