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

RC6 To Be Flipped On For Sandy Bridge, Ivy Bridge

Intel

Published on 10 December 2011 07:25 AM EST
Written by Michael Larabel in Intel
Comment On This Article

Keith Packard on Friday evening fired off an email and patch to enable RC6 power-savings support on Intel Sandy Bridge and Ivy Bridge hardware where possible. This hardware feature can decrease power usage while also increasing performance in certain workloads.

For Sandy Bridge (Gen6) hardware, RC6 will be enabled when IOMMU is not enabled while for the next-generation Ivy Bridge (Gen7) hardware, RC6 can safely be enabled always. For Ironlake and previous generations of Intel hardware, RC6 isn't being used by default.

The RC6 support state can still be manually toggled via the i915.i915_enable_rc6=1 kernel module parameter.

RC6 allows the Intel hardware to rest in a deeper power-savings state. The feature hasn't been on by default yet since it's caused havoc for some systems with stability issues and other problems.

Back in October I did some Intel Sandy Bridge RC6 benchmarks to show the increased power-savings. That's also when I discovered that RC6 can actually increase the OpenGL performance too. The increase is often quite significant. The Intel explanation about RC6 increasing the graphics performance can be found in this posting.

Recently a patch was also floated that can make RC6 go deeper, but that's not queued up for this kernel cycle.

Keith Packard & Co are hoping to push this RC6-by-default into the Linux 3.2 kernel pending any new issues coming up. However, with Linux already being concerned this cycle and already ranting about one DRM pull, I wouldn't be surprised if he rejects this patch for Linux 3.2. RC6 has been known to cause problems in the past with earlier revisions of the Intel DRM, and since this isn't a regression fix, he may try to postpone it until the Linux 3.3 kernel but we will see in the coming days what happens.

The "final" RC6 patch can be found in this mailing list message.

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. Intel Xeon E5-1680 v3 & E5-2687W v3 Compared To The Core i7 5960X On Linux
  2. Intel 120GB 530 Series SSD Linux Performance
  3. Btrfs/EXT4/XFS/F2FS RAID 0/1/5/6/10 Linux Benchmarks On Four SSDs
  4. AMD's Windows Catalyst Driver Remains Largely Faster Than Linux Drivers
Latest Linux Articles
  1. Mesa 10.5-devel Brings Some Intel Haswell HD Graphics Changes Over Mesa 10.3
  2. NVIDIA vs. Nouveau Drivers With Linux 3.18 + Mesa 10.4-devel
  3. Is The Open-Source NVIDIA Driver Fast Enough For Steam On Linux Gaming?
  4. Linux 3.18 File-System Performance Minimally Changed But Possible Regressions
Latest Linux News
  1. Amazon's Fire TV Stick: A Nice, Affordable Media Center Option
  2. Google Puts Chrome NPAPI Support On Final Countdown
  3. There's New In-Fighting Over The Future Of Compiz
  4. GTK+ Inspector Gains More Features Ahead Of GNOME 3.16
  5. Clang 3.6 Will Hopefully Have OpenMP Support
  6. A Go Front-End Could Soon Be Landing In LLVM
  7. Linux 3.18-rc6 Released, A Worrisome Regression Remains
  8. HandBrake 0.10 Brings H.265 & VP8 Encoders
  9. Gngr: A New Web Browser Focused On Privacy
  10. Linux 3.18 Kernel: Not Much Change With Intel Haswell Performance
Latest Forum Discussions
  1. Roadmap to Catalyst 14.10 ?
  2. how to configure module phoromatic ?
  3. PulseAudio 6.0 Is Coming & Other Linux Audio Plans For The Future
  4. Debian Developer Resigns From The Systemd Maintainership Team
  5. Updated and Optimized Ubuntu Free Graphics Drivers
  6. Cant get working Kaveri APU - A10-7850k
  7. Script for Fan Speed Control
  8. Debian Init System Coupling Vote Results