What is it
VDPAU (Video Decode and Presentation API for Unix) lets Nvidia cards play video with hardware acceleration. It lets any Linux, Solaris, and FreeBSD system play files, including highly complex H.264 formats produced by the Hauppauge HD-PVR, that would otherwise require a high-end multicore CPU.
Some highlights of VDPAU:
- Defines an API for GPU-accelerated decode of MPEG-1, MPEG-2, WMV, H.264, and VC-1 bitstreams.
- GT2xx and newer GPUs can additionally decode ASP (divx/xvid/mpeg4)
- Defines an API for post-processing of decoded video, including temporal and spatial deinterlacing, inverse telecine, and noise reduction.
- Defines an API for timestamp-based presentation of final video frames.
- Defines an API for compositing sub-picture, on-screen display, and other UI elements.
Note that VDPAU does not address content protection issues.
Some highlights/limitations of NVIDIA's current implementation:
- Supported on NVIDIA GPUs with the NVIDIA second generation video processors (see list further below)
- Currently, only one video stream can be decoded at a time; NVIDIA hopes to lift this restriction eventually.
VDPAU is currently supported on the following NVIDIA GPUs (driver version 180.44). An up-to-date list is available at the Nvidia link given below under 'External Links'. Feature Set, when known, is reflected in parenthesis (A/B/C). See more details regarding feature set capabilities here and the nvidia driver readme Appendix A. Supported NVIDIA GPU Products
(1) GPUs with this note may not support H.264 streams with the following widths: 49, 54, 59, 64, 113, 118, 123, 128 macroblocks (769-784, 849-864, 929-944, 1009-1024, 1793-1808, 1873-1888, 1953-1968, 2033-2048 pixels).
|Feat.||Desktop GPUs||Mobile GPUs||Motherboard GPUs||Professional GPUs||Mobile Pro. GPUs|
Rules of thumb: anything from before the 8xxx series is unsupported ; anything with the original G80 GPU (8800 GTX, 8800 Ultra, Quadro FX5600, the first 8800 GTS) is unsupported ; everything newer in the 8xxx, 9xxx and 2xx series should work if the driver supports the card.
Since video decoding is done in dedicated hardware, all supported cards have the same level of performance. Specifically, this means H.264 High 4.1, VC-1 Advanced 3, or MPEG-2 MP@HL at up to 40Mbps. Deinterlacing is performed within the shader hardware, so a more powerful card will be capable of more advanced filters at higher resolutions and framerates. Increased memory bandwidth will also help. Detailed specs on shaders, memory bandwidth, etc. can be found at this GeForce Chipsets page. Just click on the link for the relevant chipset to see the details.(see User results table below for examples).
High Def 1080i De-interlacing capabilities On Each Card
|GPU||None||One Field (1x)||Bob (2x)||Temporal (1x)||Temporal (2x)||Advanced (1x)||Advanced (2x)|
|8200||X||X||X||(>= 512Mb)||(SD only)||(>= 512Mb)||(SD only)|
|8400 PCI||X||X||X||?||(SD only)||(SD only)||(SD only)|
|8400 PCI-e (G86)||X||X||X||X (tearing at 1080i)||X (choppy at 1080i)||(SD only)||(SD only)|
|8400 PCI-e (G98)||X||X||X||X||X||(SD only)||(SD only)|
|9500 GT||X||X||X||X||X||X||X (occasional stutter, skip_chroma helps)|
|GT 210||X||X||X||X||X||X||(SD only)|
|GT 520||X||X||X||X||X||X||(SD only, maybe HD at PAL frame-rates)|
Should do all of the rest but I have not tried them.
Support started with version 180.06. Latest version available at NVIDIA's website. Bugs are fixed with every new release.
Fully supported in MythTV 0.22 and above
- Any codec support by VDPAU can be offloaded with the MythTV video player.
- Color OSD
- OSD menus
- Nothing is known not to work at the present
Enabling VDPAU in MythFrontend
"Utilities -> Setup -> TV Settings -> Playback -> Playback Profiles (3/8)"
VDPAU Playback Profiles are automatically created in current versions.
- VDPAU High Quality: use Temporal Spatial 2X (Advanced 2X) for all content. To be used with nvidia cards >= 8600GT, >= 9500GT, GT120 or >= GT220
- VDPAU Normal: use Temporal 2X for HD content, and Temporal Spatial 2X (Advanced 2X) for SD content. To be used with nvidia cards >= 8400, >= 9300, GT110 or >= GT210
- VDPAU Slim: use Bob 2X with skip chroma option, with One Field as fall back, to be used with nvidia cards >= 8200 or when VDPAU Normal doesn't work for some reasons.
Profiles using 2X deinterlacers give better motion playback than 1X ones.
You can add filters to your profile by entering:
- Utilities/Setup -> Setup -> TV Settings -> Playback -> Playback Profiles (3/8)
- Enter Edit for the if rez condition you want to change.
- Custom filters is on the second screen.
Some options will hurt performance, so don't enable unnecessarily.
This is a comma seperated list of options such as:
vdpauivtc, vdpauskipchroma, vdpaudenoise=0.5, vdpausharpen=1.0
- Sets ITU BT601 and ITU BT709 (BT709 for HD videos and BT601 for SD) colour spaces, by default or automatically
- Why/when it should be used: always, used in MythTV default profiles
- Set as vdpaucolorspace=[auto|itu709|itu601]
- example: vdpaucolorspace=auto
- vdpaustudio (removed in 0.25 [a9d80d8], available as a toggle now)
- Will prevent converting RGB studio (16-235) levels to RGB PC levels (0-255)
- Why/when it should be used: If you are using a TV/projector for playback: almost always. Set by default in default playback profiles
- Type: toggle
- Example: vdpaustudio
- vdpaubuffersize (remove this vdpaubuffersize if running 0.25, it is now known as vdpaubuffercount with 0.25 [a9bf1d3] and not required at this time)
- VDPAU video buffer size
- Why/when it should be used: If some H264 videos don't play properly
- The valid range is 6 to 50 (default 17)
- Example: vdpaubuffersize=14
- Enabling VDPAU inverse telecine, requires Basic or Advanced deinterlacer
- Why/when it should be used: When playing telecined content.
- Type: toggle
- Example: vdpauivtc
- Enabling Skip Chroma Deinterlace
- Why/when it should be used: It may help with lower-end graphic cards. This is the default for VDPAU Low quality profile
- Type: toggle
- Example: vdpauskipchroma
- VDPAU Denoise
- Why/when it should be used: To reduce visual noise or "grain" in the picture. This seems to reduce both chroma and luminance noise (Can anyone confirm this?)
- Will hurt performance
- The valid range is 0.0 to 1.0, with 0.0 disabling it
- Example: vdpaudenoise=0.5
- VDPAU Sharpen
- Why/when it should be used: To soften or sharpen the picture. Sharpening the picture will also sharpen any other artifacts such as noise, so this should generally be used with other filters.
- Will hurt performance
- The valid range is -1.0 to 1.0, with 0.0 disabling it
- Example: vdpausharpen=0.7
- enables High Quality scaling
- Why/when it should be used: If you have a VDPAU features C card (e.g. nVidia 210, 220, Ion 2)
- Type: toggle
- Example: vdpauhqscaling
Compiling MythTV with VDPAU
For Myth to support VDPAU it must be built in. MythTV's compilation script supports this. To enable it use the configure script and the --enable-vdpau option.
The following is an example of how to compile MythTV with VDPAU:
./configure --prefix=/usr --enable-proc-opt --disable-joystick-menu \ --disable-firewire --disable-hdhomerun --disable-xvmcw \ --enable-vdpau --disable-directfb --enable-opengl-vsync
./configure --prefix=/usr --enable-opengl --enable-mytharchive \ --disable-mythbrowser --disable-mythcontrols --disable-mythflix \ --enable-mythgallery --disable-mythgame --enable-mythmusic --disable-mythnews \ --disable-mythphone --enable-mythvideo --disable-mythweather \ --disable-mythzoneminder --disable-mythmovies
- No AGP cards support this feature (PCI cards exist but lack the necessary bandwidth for non-VDPAU HD)
- Warning: Do not install the vdpau beta driver unless you intend to use an NVidia-based video cards exclusively thereafter. Merely installing the nvidia driver breaks digital playback on Intel (and probably any other) video/graphics cards. The nvidia installer *replaces* standard header files (/usr/include/glext.h, glext.h,glxext.h and glx.h) and library files (/usr/lib/libGLcore.so, libGL,so, libGLU.so and libGL.la), with nvidia specific versions which breaks OpenGL playback on other graphic cards. (The 180 series drivers do appear to be usable with non-vdpau capable nvidia GPUs (6200 etc.))
- If you wish to try an nvidia video board instead of your other video/graphic chipset, be careful. Make a mythconverg database backup, and note the revision of your present working version. In addition, it would be wise to extract the NVidia pkg.run file (NVIDIA-LINUX....pkg.run -x) and make backups of the original files for which copies exist in the ../include/GL, ../lib and ../X11R6 folders. The package help states that the option '--no-opengl-headers' will skip installing the Nvidia OpenGL headers, however it appears that the other libraries will be replaced anyway. It also does not appear to be the case that the '--uninstall' option actually reverses the install, as the orginal files do not appear to be retained. This is a real time-killer ( and WAF killer) and may require a complete re-installation of the system if you wish to revert to a different family of GPU chip.
- In MythTV, it is not possible to configure video playback profiles to filter based on video format (only by resolution). So it is not currently possible to use VDPAU for H.264/HD-PVR and Xv for Mpeg2.
- Off-loading to the GPU may increase its heat out-put. It may seem obvious, but check your GPU temperature and cooling arrangements.
- Many playback issues can be resolved by making sure enough memory has been allocated to the video card, 256MB is a bare minimum requirement and 512MB is strongly recommended. For on-board video this is usually configured via the "GPU Window" BIOS option.
The following configuration changes should be used to prevent issues with VDPAU when used with MythTV:
- Enable Extra Audio Buffering (same page)
- Disable Real-Time Priority (same page) (or limits.conf) if you have intermittent playback freezes (playback stops for about 30 seconds,the computer is COMPLETELY unresponsive during this period and then playback resumes as is nothing had happened)
- Adding 'Option "TripleBuffer" "true"' to the Device section of xorg.conf (following the 'Driver nvidia' line) will allocate more memory buffers to 2D playback (and less to 3D).
Option "TripleBuffer" "True"
Disabling the Composite Extension
Tearing of the OSD over a perfect video playback can be avoided by stopping playback, exiting playback, and re-starting playback of the stream. (No idea why this works..only that it does.)
To prevent vertical and horizontal tearing of the image when viewing live tv or recordings, run the following to disable X Composite Extension (may also cure the all white/gray OSD):
sudo nvidia-xconfig --no-composite
or with the following lines in /etc/X11/xorg.conf:
Section "Extensions" Option "Composite" "Disable" EndSection
This may also help eliminate sporadic single-frame stuttering glitches (e.g. slight jerks in long panning shots or scrolling backgrounds).
GPU Power Management
Another common problem is the "adaptive clocking" PowerMizer capability of some NVidia cards: if this is active, frames will occasionally be dropped as the clock rate is adjusted. To switch to performance mode temporarily, use the nvidia-settings application in interactive mode to set "Preferred Mode" to "Prefer Maximum Performance" under each GPU's "PowerMizer" page.
NOTE: YOU MUST REBOOT YOUR SYSTEM AND HAVE POWERMIZER DISABLED, AS DESCRIBED BELOW, TO CORRECT ANY PROBLEMS CREATED BY RUNNING POWERMIZER.
Unfortunately, due to a bug in recent versions of nvidia-settings, this setting may not be preserved across reboots: in order to switch to performance mode automatically, you may need to create a script that executes:
nvidia-settings -a '[gpu:0]/GPUPowerMizerMode=1'
for each GPU (in this case, for GPU 0). Note that this must be done after X starts: if you use GDM to manage your console logins, /etc/gdm/Init/Default may be a good place to put this. Confirm the setting by running:
nvidia-settings -q '[gpu:0]/GPUPowerMizerMode'
after the following reboot.
Adding "vdpaubuffersize=32" (or higher: eg. 42 works well for the Zotac HD-ID11 box) in the list of filters in Playback Settings may help with artifacts during playback. Remove this filter if running on 0.25 or later.
CPU Frequency Scaling
If you are using CPU frequency scaling and are having problems playing HD video with VDPAU (stuttering video or audio) then it maybe that your processor is causing a bottleneck. Two known issues exist:
- Some AMD processors reduce the bus speed along with the CPU clock, at the lowest scaling level this may be enough to cause VDPAU problems in transferring data fast enough across the bus. One solution is to increase the minimum speed by changing the value in /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq, see sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies for a list of valid values. e.g. On for a CPU with a min speed of 1000Mhz you may need to bump the min speed to 1800Mhz.
echo 1800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
- If frequency scaling is still causing problems then it may be due to too high a threshold being set for frequency changes. Ubuntu for example uses a ridiculous threshold of 95% utilisation per core which is beyond what many userspace applications are even allowed to achieve at their priority level. So an application like MythTV would be choking and the ondemand governor would never increase the CPU frequency to cope. You should first check that your distribution has a reasonable value configured for the 'up threshold', what's reasonable will vary but 50% is a good place to start.
intel_idle Power Management
You may be seeing a problem with intel_idle if you are using an Atom- or i3/5/7-based system (e.g., the Zotac MAG): this driver causes occasional stuttering when power management is enabled. You can disable this by adding
to your boot options (e.g., to GRUB_CMDLINE_LINUX in /etc/default/grub, followed by executing update-grub). After rebooting, confirm that power management has been disabled:
$ cat /proc/acpi/processor/CPU0/info | grep power power management: no
Disabling intel_idle power management actually results in power management falling back to ACPI, which does not appear to have the same stuttering issue.
Note: Reports on 1080i content are of greatest interest for deinterlacers. Do not list a deinterlacer if testing on progressive content like 720p. If reports for 720p and 1080i differ (as they will if using a deinterlacer) consider making two entries or indicating the difference in your success/fail results.
|Chipset||Onboard / Allocated Memory||Driver||De-interlacer||Version||Source||OSD||Theme||Window Manager||Display res||Working||CPU Usage when playing||Comments|
|8200 IGP||512mb||180.29||Temporal 2x||r20038 trunk||BBC HD H.264 1080i 21Mb/s||Metallurgy||Terra||KWin||1440x900||Yes||Athlon 4850e 2.5Ghz 10-15%||Some amount of tearing. Visual artifacts for the first 20 seconds.|
|8200 IGP||512mb||180.29||Temporal 2x||r20038 trunk||HD-DVD VC-1 1080p 35Mb/s||Metallurgy||Terra||KWin||1440x900||Yes||Athlon 4850e 2.5Ghz 35%|
|8200 IGP - Asus M3N78-VM||512mb||256.35||Temporal 1x||0.23-fixes 25260||HD-PVR h.264 1080i 14Mb/s||BlackCurves||Mythbuntu||Gnome||1152x720||Yes||Athlon 64 X2 4800+ 7%||vdpaubuffersize=64,vdpauskipchroma|
|Sparkle SFPC84GS512U2LP GeForce 8400 GS PCI||512mb||180.35||Temporal 1x HW||0.21-fixes w/patch||OTA 720p and 1080i||Retro||Retro||fluxbox||VGA (analog) 1280x1024||Yes||AMD Geode NX1750 (1.4 Ghz), ~30%||Looks super, OSD set to non-fade. Bob 2x is *almost* useable as is Temporal 2x HW. One field also works well.|
|Asus EN8400GS Silent PCIe (G98 chipset, 567 MHz Core Clock)||512mb||180.29||Temporal 1x HW||0.21-fixes w/VDPAU patch||OTA HDTV (1080i & 720p)||Retro||Retro||Fluxbox||1080p||Yes||AMD BE-2350 (2.1 GHz) 2% - 5%||Temporal 1x HW and One Field are the only deinterlacers that don't cause jerky picture and out of sync audio. All h264 test files from HD Playback Reports are nice and smooth.|
|Asus EN8400GS Silent PCIe (G98 chipset, 500MHz Core/333Mhz Mem)||256mb||180.53||Temporal 1x HW||0.22||OTA HDTV (1080i & 720p)||default||default||mwm||1080p||Yes||Pentium-D (3.4 GHz) 2% - 5%||Temporal 1x HW and Bob deinterlacers work ok. Temporal 1x HW is a little jerky on some stations. H.264 1080p files play perfect|
|Asus EN8400GS Silent PCIe (G98 chipset, 612 MHz GPU Clock)||512mb||180.29||Temporal 2x HW||0.21-fixes + patch r20005||HDHomeRun (1080i+720p), FireWire (1080i+720p)||Retro||Retro||Ratpoison||1080p||Yes||Pentium 4 3000 5% -10%||Temporal 2x/1x work great, albeit with slight stuttering when OSD displays; Advanced 2x/1x works well only with SD video. Bob 2x works too, but pointless given Temporal 2x.|
|GeForce 9300. Motherboard Asus P5N7A-VM||256MB||180.22||One Field 1x HW||0.21-fixes + patch||From disk (originally from pcHDTV HD-5500)||Mythbuntu||Mythbuntu||Xfce||1080p||Yes||Intel(R) Core(TM)2 Duo CPU E7400 @ 2.80GHz 10% overall||Slight oddness on top line. Before VDPAU, CPU usage at .74. I am including complete load average, mythfrontend.real at 5-7%.|
|GeForce 9200. Motherboard Jetway JNC62K||512MB (shared)||180.27||One Field 1x HW||0.21-fixes + Jean-Yves Avenard testing patches||SD MPEG-2 DVB, SD H.264, 720p H.264 sample videos||Mythbuntu||Mythbuntu||Xfce||1080p||Yes||AMD Athlon 64 X2 4850e 2.5GHz 2-5%||No problems so far - before VDPAU, CPU usage at 80% and whirring fans.|
|Quadro NVS 140M in a Lenovo T61 Laptop||512MB (shared)||180.29||One Field 1x HW||0.21-fixes + patches||SD MPEG-2, HD MPEG-2 720p and 1080i from either QAM tuner or Firewire Cable Box||Blue||Retro||Gnome||1440x900||Yes||Core 2 Duo T9300 2.5 GHz ~50% on one core||OSD sometimes fails to show. Before VDPAU, CPU usage was up to 90% on one core used by Myth and additional 20-30% used by X.|
|9300 IGP (EVGA 113-YW-E115-TR)||512mb||180.29 (Debian experimental package -1)||Temporal 2x||r20207 trunk||OTA HD 1080i||Blue||Terra||fvwm||1080p||Yes||Core 2 Duo E5200 2.5GHz <10%||Jerky playback w/ Advanced 2x on 1080i. Had to set 512MB GPU mem in BIOS to play 1080i at all. Using Advanced 2x w/o problems for 480i.|
|GeForce 9300. Motherboard Asus P5N7A-VM||512MB (Shared)||180.51||Temporal 2x HW||0.21-fixes + patch||TechnoTrend Premium DVB-C 2300 on remote backend||Mythbuntu||Mythbuntu||Xfce||720p||Yes||Intel(R) Core(TM)2 Duo CPU E5400 @ 2.50GHz CPU Load approx 5-7 %.||Advanced (2x, Hw) used for 720x576i SD, had to change to Temporal 2x HW to have smooth playback of 1080i|
|GeForce 9400GT. Motherboard Gigabyte Intel G35||512MB (Dedicated)||180.60||Advanced 2X HW for SD, Temporal 2x HW for HD||0.21-fixes + VDPAU patch||DVB-T on remote backend||Mythbuntu + Avenard repo||Mythbuntu||Xfce||1080P||Yes||Intel(R) C2D CPU E8200 @ 2.66GHz CPU Load approx 4-5 %.||Advanced (2x, Hw) used for <= 720, Temporal 2x HW or Advanced 1X HW for > 720|
|GeForce 9400M. Motherboard Gigabyte GA-E7AUM-DS2H||256MB (Shared)||180.60||Advanced 2X HW for SD, Temporal 2x HW for HD||0.21-fixes + VDPAU patch||DVB-T on remote backend||Mythbuntu + Avenard repo||Mythbuntu||Xfce||1080P||Yes||Intel(R) C2D CPU 8500 @ 3.16GHz CPU Load approx 4-5 %.||Advanced (2x, Hw) used for <= 720, Temporal 2x HW or Advanced 1X HW for > 720|
|GeForce 9400M. Apple macbook||256MB (Shared)||180.60||Advanced 2X HW||0.21-fixes + VDPAU patch||DVB-T on remote backend||Mythbuntu + Avenard repo||Mythbuntu||Xfce||1280x800||Yes||Intel(R) C2D CPU @ 2.4 GHz CPU Load approx 4-5 %.||Advanced (2x, Hw) for all content on laptop display|
|GeForce 9500GT (PNY). Intel D945PVS Mobo||1024MB (Shared)||256.44||Advanced 2X HW||0.23-fixes||2xFirewire on local backend||RHEL6 Beta 2||ATRPMS Build 235 Bijou vuvuzela||KDE||Component Video 480p / 1080i||Yes||Intel(R) P4D CPU @ 2.8 GHz CPU Load approx 5-10 %.||-|
|nvidia ion - GeForce 9400. Zotac IONITX-C||512MB||180.51||Temporal 2X HW||0.21-fixes + VDPAU patch (20549)||ATSC 720p & 1080i + HDPVR 720p||blootube||blootube||fluxbox||720p||Yes||Atom(TM) CPU 230 @ 1.60GHz CPU Load approx 4-7 %.||Works great even w/ single core atom. No fans. 20W power draw.|
|NVIDIA GeForce 8200 Motherboard ASUS M3N78-VM||512MB (Shared)||190.18.03||Bob 2x||trunk 21145||HD-PVR 1080i + 720p||blootube||blootube||KDE||1080p||Yes||Athlon 64 X2 6000 3.0GHz 1-3%||No tearing. Audio stuttering with Advanced 2x/1x. Box 2x works.|
|NVIDIA GeForce 8200 Motherboard ASUS M3N78-VM||512MB (Shared)||304.43||Bob 2x||0.25.2 +fixes 20120802 46cab93- 0ubuntu1||DVB YLE HD (1080i?)||Mythcenter-wide||Mythcenter-wide||Xfce||1920x1080||Yes||Athlon 64 X2 3800+ 5-7%||Got rid of stuttering with scaling_min_freq 1800000|
|NVIDIA GeForce 8300 Motherboard ASUS M3N78 PRO||512mb (shared)||185.18.14||Temporal 2x||trunk 20694M||BBC HD H.264 1080i 21Mb/s||blootube||Terra||KDE||1920x1080||Yes||Athlon 64 X2 5200 2.7Ghz 10-15%||Temporal 2x/1x work great, albeit with slight stuttering when OSD displays; Advanced 2x/1x still stutter. Bob 2x works too, but pointless given Temporal 2x.|
|NVIDIA GeForce 9500GT Motherboard Gigabyte GA-M571SL1-S4||512mb||190.53||Advanced 2x HW||0.22-fixes||HD-PVR Comcast max variable bitrate||Blue Abstract||Blue Abstract||Gnome||720p||Yes||Athlon X2 5200+ 2.7GHz 8%-10%||Rock solid at 720p|
|NVIDIA GT 220 ||1024mb||195.36.15||Advanced 2x HW||0.23-fixes||HDHomeRun (1080i+720p), FireWire (1080i+720p)||Mythbuntu||Mythbuntu||Xfce||1080p||Yes||Athlon X2 2400 8%-10%||Works great.|
|NVIDIA GT 430||1024mb||210.19.21||Advanced 2x HW||0.23-fixes||FireWire (1080i+720p, FiOS) and h264 1080i||Black Curves||Mythcenter-Wide||KDE 3.5||1080i||Yes||Athlon X2 4400 20% at 1GHz||Works great.|
|NVIDIA ION GeForce 9400M ZOTAC IONITX-B-E||512mb||195.36.15||Advanced 2x HW||0.23-fixes||HDHomeRun (1080i+720p), FireWire (1080i+720p)||Mythbuntu||Mythbuntu||Xfce||1080p||Yes||Atom(TM) CPU 230 @ 1.60GHz CPU Load approx 4-7 %.||Works great.|
|NVIDIA ION (GeForce 9400M variant) ZOTAC IONITX-A-U||512MB (Shared)||195.36.24||Temporal 2x HW (HD), Advanced 2x HW (SD)||0.23-fixes||ATSC 720p/1080i MPEG2, 720p/1080p h264 MKVs (Remote backend)||Metallurgy||Arclight||Xfce||1080p||Yes||Intel Atom 330 1.6GHz — 3 - 8% in Myth; 0 - 2% in mplayer (set as external player for mkv files)|| Needed to install two matched RAM sticks for dual-channel mode, or GPU memory bandwidth was insufficient. Initially tried with one 2GB stick; Temporal 2x at 1080i was very jerky, but works perfectly with two 1GB sticks.|
Also, MB is running with nothing but RAM added; PXE boot + NFS root, with excellent performance. (File access hits 110 - 120MB/sec, limited only by GigE speeds.)
|NVIDIA GT 220 ||1024mb||260.19.44||Advanced 2x HW||0.24-fixes||950Q - QAM (Time Warner for HD Local), PVR500 (Dual analog for SD Cable)||Scientific Linux 6.0||Scientific Linux 6.0||Gnome||1080p||Yes||Intel(R) Core(TM)2 Duo CPU E4400 @ 2.00GHz||no issues running full 2x on 1080i content.|
|NVIDIA GT 520 (using Asus silent model) ||1024mb||275.09.07||Advanced 2x HW||0.24-fixes||DVB-T on remote backend||Mythcenter-Wide||Mythcenter-Wide||Fluxbox||1680x1050||Yes||Amd Opteron 146 (throttled to 1GHz) ~ 5% CPU||no issues running Advanced 2x on 1080i content. Tested with Tennis, Australian Rules Football and Motor Sports|
|NVIDIA GT 520 ||1024mb||260.19.44||Advanced 2x HW||0.25||Ceton InfiniTV on Verizon FIOS Cable Card||Scientific Linux 6.0||Scientific Linux 6.0||Gnome||1080p||Yes||Intel(R) Core(TM)2 Duo CPU E4400 @ 2.00GHz||no issues running full 2x on 1080i content.|
|NVIDIA GeForce 210 ||512mb||195.36.15||Advanced 2x HW||0.25||HDHomeRun (1080i+720p), FireWire (1080i+720p)||Mythbuntu Default||Mythbuntu Default||Xfce||720p||Yes||AMD Phenom II X4@2.8Ghz CPU Load ~5%||Works Great for 1080i, 720p (both MPEG-2 and H.264)|
Note: This list is dependent on the driver version. This currently points to the version 260.19.36 README file appendix. Newer versions of the driver may add other GPUs to the list and other capabilities.