- Feature Matrix for Free Radeon Drivers
- VSYNC
- KMS Power Management Options
- Linux kernel parameters
- Decoder ring for engineering vs marketing names
- Radeon Graphics/Compute Hardware
- Radeon Display Hardware (DCE - Display and Compositing Engine; DCN - Display Core Next)
- Radeon UVD (Unified Video Decoder) Hardware
- Radeon VCE (Video Compression Engine) Hardware
- Radeon VCN (Video Core Next) Hardware
- Where to get the drivers
- Where to file defect reports
- Documentation
- Links
- Footnotes
Feature Matrix for Free Radeon Drivers
This page is only for free Radeon drivers using KMS. radeon (xf86-video-ati) for 2D; radeon, r200 Mesa and r300, r600, radeonsi Gallium drivers only. THIS PAGE IS NOT FOR FGLRX/CATALYST DRIVERS PROVIDED BY AMD/ATI.
See RadeonFeatureUMS for radeon in UMS.
See radeonhd:feature for radeonhd.
Also check out the GalliumStatus and ATIRadeon at DRI wiki.
- "DONE" means that it is implemented and relatively bug-free.
- "MOSTLY" means that it is implemented but has some known bugs.
- "WIP" means that someone has started on the initial implementation.
- "BIOS" means only if supported by your BIOS. No software support. Yet.
- "N/A" means that the feature is not supported by the hardware.
- "N/N" means that the feature will not be implemented, because a better alternative is or will be available.
- "TODO" means that someone needs to write the code. The required knowledge to write the code may or may not be known. Please ask on #radeon if you want to get your feet wet on this.
- "UNKNOWN" means that the current status of this item isn't known. You are free to update it if you know.
(via env variable / drirc) DONE DONE DONE DONE DONE DONE DONE DONE 7 DONE DONE DONE
VSYNC
There are several mechanisms involved in tear-free rendering due to limitations in X.
3D driver environment variable
- vblank_mode - selects whether or not the 3D application should synchronize to vblank.
DDX driver options
- EnablePageFlip - This option enables the use of pageflipping (switching the display controller's base address pointer) rather than blits for GL buffer swaps. It only applies to fullscreen GL apps. Pageflipping is always synced to vblank at the moment.
- SwapBuffersWait - This option prevents tearing for GL buffer swaps by waiting to update the front buffer until scanout has passed the area of the screen the GL buffer swap is going to blit to.
- EXAVSync - This option prevents tearing for EXA operations by waiting to update the front buffer until scanout has passed the area of the screen the EXA operation is going to render to.
Xv Attribute
- XV_VSYNC - This option prevents tearing when playing back videos using Xv by waiting to update the video image until scanout has passed the area of the screen displaying the video. It only prevents tearing if Xv is rendering directly to the front buffer. If you are using a compositer, this does not prevent tearing because Xv is rendering to an offscreen buffer and the compositor copied it to the front buffer.
KMS Power Management Options
Kernel 2.6.35 or newer is required. The pm code supports three basic methods:
- "dynpm"
- "profile"
- "dpm"
You can select the methods via sysfs. Echo "dynpm" or "profile" to /sys/class/drm/card0/device/power_method. "dpm" support, must be selected at boot (via radeon.dpm=1) and is only supported on R6xx and newer asics.
Controlling the fan speed directly is not possible (and would be very dangerous), but it can be lowered by setting lower power profile.
The "dynpm" method dynamically changes the clocks based on the number of pending fences, so performance is ramped up when running GPU intensive apps, and ramped down when the GPU is idle. The reclocking is attemped during vertical blanking periods, but due to the timing of the reclocking functions, doesn't not always complete in the blanking period, which can lead to flicker in the display. Due to this, dynpm only works when a single head is active.
The "profile" method exposes five profiles that can be selected from:
- "default"
- "auto"
- "low"
- "mid"
- "high"
Select the profile by echoing the selected profile to /sys/class/drm/card0/device/power_profile.
- "default" uses the default clocks and does not change the power state. This is the default behavior.
- "auto" selects between "mid" and "high" power states based on the whether the system is on battery power or not. The "low" power state are selected when the monitors are in the dpms off state.
- "low" forces the gpu to be in the low power state all the time. Note that "low" can cause display problems on some laptops; this is why auto does not use "low" when displays are active.
- "mid" forces the gpu to be in the "mid" power state all the time. The "low" power state is selected when the monitors are in the dpms off state.
- "high" forces the gpu to be in the "high" power state all the time. The "low" power state is selected when the monitors are in the dpms off state. The "profile" method is not as agressive as "dynpm," but is currently much more stable and flicker free and works with multiple heads active.
The "dpm" method uses hardware on the GPU to dynamically change the clocks and voltage based on GPU load. It also enables clock and power gating.
Power management is supported on all asics (r1xx-evergreen) that include the appropriate power state tables in the vbios; not all boards do (especially older desktop cards). "dpm" is only supported on R6xx and newer asics.
Thermal sensors are implemented via external i2c chips or via the internal thermal sensor (rv6xx-evergreen only; supported in 2.6.36 or newer); not all OEMs implement a thermal sensor. To get the temperature on asics that use i2c chips, you need to load the appropriate hwmon driver for the sensor used on your board (lm63, lm64, etc.). The drm will attempt to load the appropriate hwmon driver. On boards that use the internal thermal sensor, the drm will set up the hwmon interface automatically. When the appropriate driver is loaded, the temperatures can be accessed via lm_sensors tools or via sysfs in /sys/class/hwmon.
Linux kernel parameters
Try modinfo -p radeon to find up-to-date parameters. To check default values look at drivers/gpu/drm/radeon/radeon_drv.c or drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c in Linux kernel source. To check current values look at /sys/class/drm/card*/device/driver/module/holders/radeon/parameters/ or /sys/class/drm/card/device/driver/module/holders/amdgpu/parameters/*
Decoder ring for engineering vs marketing names
There are a lot of marketing names. For an authoritative list of marketing to family relations, please see this link.
Radeon Graphics/Compute Hardware
Radeon Display Hardware (DCE - Display and Compositing Engine; DCN - Display Core Next)
Radeon UVD (Unified Video Decoder) Hardware
Radeon VCE (Video Compression Engine) Hardware
Radeon VCN (Video Core Next) Hardware
Where to get the drivers
- Xorg radeon DDX (xf86-video-ati)
- Xorg amdgpu DDX (xf86-video-amdgpu)
- Mesa 3D driver (radeon, r200, r300g, r600g, radeonsi)
- KMS DRM (Linux Kernel)
- libdrm (libdrm_radeon, libdrm_amdgpu)
Where to file defect reports
http://bugs.freedesktop.org using the following values for Product : Component...
- Xorg radeon DDX - xorg : Driver/Radeon or Driver/AMDgpu
- Mesa 3D driver (1xx) - Mesa : Drivers/DRI/Radeon
- Mesa 3D driver (2xx) - Mesa : Drivers/DRI/r200
- Mesa 3D driver (3xx-5xx) - Mesa : Drivers/Gallium/r300
- Mesa 3D driver (6xx-NI) - Mesa : Drivers/Gallium/r600
- Mesa 3D driver (SI-VI) - Mesa : Drivers/Gallium/radeonsi
- KMS DRM aka Kernel graphics driver - DRI : DRM/Radeon or DRM/AMDgpu
Documentation
- A presentation about R600 for very beginners
- AMD R3xx 3D Register Reference
- AMD R5xx Acceleration
- AMD R6xx/R7xx 3D Register Reference
- AMD R6xx/R7xx Acceleration
- AMD Evergreen 3D Register Reference
- AMD Cayman/Trinity 3D Register Reference
- AMD Evergreen/Northern Islands Acceleration
- AMD Southern Islands 3D Register Reference
- AMD Sea Islands 3D Register Reference
- AMD Southern Islands/Sea Islands Acceleration
- AMD rv630
- AMD rs690
- AMD M56
- AMD m76
- AMD HDA audio verbs
- AMD R6xx shader ISA
- AMD R7xx shader ISA
- AMD Evergreen shader ISA
- AMD Cayman/Trinity shader ISA
- AMD Southern Islands Series ISA
- AMD Sea Islands Series ISA
- AMD Volcanic Islands Series ISA
- AMD "Vega" Series ISA
- AMD "Vega" 7nm Series ISA
- AMD CDNA Series ISA
- AMD CDNA2 Series ISA
- AMD RDNA Series ISA
- AMD RDNA2 Series ISA
- AMD RDNA3 Series ISA
- AMD RDNA3.5 Series ISA
- AMD RDNA4 Series ISA
Links
- Wikipedia AMD GPUs
- AMD Hardware Documentation
- AMD OpenCL and Compute Resources
- AMD Developer Guides (RS780/RS880, SB7xx, etc.)
Footnotes
1 Kernel 3.4 required
2 Depends on the OEM board. Max of 2 (evergreeen-SI) or 3 (CI) non-Displayport displays with independent timing.
3 Requires a 3D driver with shader support
4 RV770, RS780/880, R6xx require kernel 3.18
5 There are two versions of hybrd graphics: MUXed and MUX-less. MUXed have a display MUX to switch the displays between the discrete and integrated cards. MUXed systems can be switched using vgaswitcheroo. MUX-less do not have a display MUX and the displays are only connected to the integrated card. On MUX-less systems, the discrete card is solely for rendering, not display. X Server 1.14 is required to support rendering and display from different cards. Most new laptops (2011+) are MUX-less.
7 Kernel 3.10 required
12 Kernel 3.6 required
14 Needs piglit and Lightsmark testing before enabling by default, see mesa commit 12dcbd595
15 Currently enabled by default. It can be disabled by setting the environment variable R600_DEBUG=nohyperz.
16 Hardware doesn't support ARB NPOT textures fully.
17 Kernel 3.14 required. For older kernel, apply this kernel patch: http://www.spinics.net/lists/dri-devel/msg52745.html
18 LLVM 3.9 and Kernel 4.7 required
19 OpenGL 4.2 is currently only supported on CYPRESS, CAYMAN and ARUBA. All other chips are currently limited to OpenGL 3.3
20 LLVM 3.9 required
22 Older kernels require loading radeon with the audio parameter set to 1 (e.g., add radeon.audio=1 on the kernel command line in grub).
23 Kernel 3.3 required
24 Kernel 3.5 required
26 i2c chip
28 i2c chip or internal sensor
33 See http://dri.freedesktop.org/wiki/GalliumCompute
34 None
35 ARUBA only
36 No TV-out support on R4xx