1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

Intel Flip-Flops Again: RC6 Disabled For Linux 3.2

Linux Kernel

Published on 28 December 2011 07:57 PM EST
Written by Michael Larabel in Linux Kernel
3 Comments

Ouch, Intel at the last minute has -- once again -- had to disable RC6 power savings support from their open-source Linux graphics driver for Sandy Bridge hardware.

Earlier this month I wrote that Intel would be attempting to enable RC6-by-default for Sandy Bridge and Ivy Bridge graphics processors in the forthcoming Linux 3.2 kernel. RC6 is capable of saving power for mobile (and desktop) systems by allowing the integrated graphics processor to rest in a lower power-state, while at the same time is capable of boosting OpenGL performance.

Earlier this month I questioned whether Linus Torvalds would allow Intel RC6 to be enabled by default outside of the merge window considering this feature has been problematic in the past -- causing stability issues and hangs for some systems -- and he was already mad at one 3.2 DRM pull, but it ended up getting accepted.

Along with that merge this month was enabling of semaphores by default, which was then reverted last week over regressions. Now this week Keith Packard sent over a patch to Linus Torvalds to revert the RC6 by default.

So the Linux 3.2 kernel will not have RC6 by default for Sandy Bridge since it's still causing problems for some systems with this Linux driver, one year after the hardware first shipped. This commit is what does the flip-flop, again (it's been a similar story before).

Those wanting to take advantage of this feature and aren't hit by system freezes, you can pass i915.i916_enable_rc6=1 as a kernel command-line parameter to enable this power conservation feature.

Maybe with the Linux 3.3 kernel Intel will finally get lucky?

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. NVIDIA GeForce GTX 970 Offers Great Linux Performance
  2. CompuLab Intense-PC2: An Excellent, Fanless, Mini PC Powered By Intel's i7 Haswell
  3. From The Atom 330 To Haswell ULT: Intel Linux Performance Benchmarks
  4. AMD Radeon R9 285 Tonga Performance On Linux
Latest Linux Articles
  1. Ubuntu 14.10 XMir System Compositor Benchmarks
  2. Btrfs RAID HDD Testing On Ubuntu Linux 14.10
  3. Ubuntu 14.10 Linux 32-bit vs. 64-bit Performance
  4. AMD Moves Forward With Unified Linux Driver Strategy, New Kernel Driver
Latest Linux News
  1. What Linux Benchmarks Would You Like To See Next?
  2. Open-Source, Linux Support For Corsair Link Devices Slowly Materializing
  3. Cairo-Dock 3.4 Shows A Lot Of Progress, Works Toward EGL/Wayland Support
  4. Mesa 10.4 Tentatively Planned For Early December
  5. SteamOS Update 145 Brings Compositor, Update Fixes
  6. GStreamer 2014 Conference Videos Posted: Wayland, HTML5, 3D
  7. Nouveau Now Supports DRI3 Without GLAMOR
  8. Features Of The Linux 3.18 Kernel
  9. Debian Now Defaults To Xfce On Non-x86 Desktops
  10. Phoenix Is Trying To Be An Open Version Of Apple's Swift
Latest Forum Discussions
  1. Linux hacker compares Solaris kernel code:
  2. HOPE: The Ease Of Python With The Speed Of C++
  3. Users/Developers Threatening Fork Of Debian GNU/Linux
  4. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  5. AMD Releases UVD Video Decode Support For R600 GPUs
  6. Proof that strlcpy is un-needed
  7. xbox one tv tuner
  8. Bye bye BSD, Hello Linux: A Sys Admin's Story