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View Full Version : [ubuntu] Ubuntu + NVIDIA + Twinview == video tearing



TheBuzzSaw
September 7th, 2010, 11:39 PM
Core 2 Quad 2.4 GHz
4 GB RAM
NVIDIA GTX 275

I have two monitors enabled using Twinview: AOC 2236 (1920x1080) and DELL 1707FP (1280x1024).

In general, there is no tearing. I have to whip a window around violently to make it tear badly. However, video is extremely sensitive. I really would like to watch 1080p video, but the tearing is unbearable at times. In Windows 7, I have no tearing at all.

Any tips? Any help? I've hunted for solutions. I found several suggesting I make certain tweaks in my Nvidia control panel and in my compiz settings. I've tried these things to no avail.

My xorg file:


# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 260.19.04 (buildmeister@builder101) Thu Sep 2 19:14:35 PDT 2010

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 256.44 (buildmeister@builder103.nvidia.com) Thu Jul 29 01:52:36 PDT 2010

Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "InputDevice"

# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "AOC 2236"
HorizSync 30.0 - 80.0
VertRefresh 56.0 - 75.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce GTX 275"
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-0: nvidia-auto-select +1920+0, DFP-1: nvidia-auto-select +0+0"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "1"
Option "TwinViewXineramaInfoOrder" "DFP-1"
Option "metamodes" "DFP-0: nvidia-auto-select +0+0, DFP-1: nvidia-auto-select +1920+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection


I'm not a big expert regarding my xorg file, but I have a few observations.

(1) -- Where is my DELL monitor? It doesn't seem to be mentioned/configured.

(2) -- Would it be a problem if my two monitors have differing refresh rates? I suspect my DELL monitor runs at 60 Hz, while the AOC runs at 75 Hz. (I can't find specific specs using Google.)

ShadowTek
September 8th, 2010, 04:56 AM
Default Compiz settings caused tearing for me, but setting sync-to-vblank fixed it.
http://tombuntu.com/index.php/2009/09/20/make-compiz-run-smoothly-and-without-tearing/

TheBuzzSaw
September 8th, 2010, 07:45 AM
Default Compiz settings caused tearing for me, but setting sync-to-vblank fixed it.
http://tombuntu.com/index.php/2009/09/20/make-compiz-run-smoothly-and-without-tearing/

I appreciate the help... but did you even read my post?

ShadowTek
September 8th, 2010, 03:30 PM
I appreciate the help... but did you even read my post?

Yes, I clearly read the part where you failed to specify exactly what Compiz modifications you have already tried.


Any tips? Any help? I've hunted for solutions. I found several suggesting I make certain tweaks in my Nvidia control panel and in my compiz settings.

TheBuzzSaw
September 8th, 2010, 03:40 PM
Yes, I clearly read the part where you failed to specify exactly what Compiz modifications you have already tried.

It's an issue with Twinview. I am working on two monitors. That makes those simple solutions useless.

Diego318
September 24th, 2010, 03:37 AM
Default Compiz settings caused tearing for me, but setting sync-to-vblank fixed it.
http://tombuntu.com/index.php/2009/09/20/make-compiz-run-smoothly-and-without-tearing/


Are you talking about setting sync to vblank in nvidia-settings or in Compiz settings?

ShadowTek
September 24th, 2010, 04:30 AM
I think sync to vblank in nVidia settings is/was already checked by default. Regardless, it didn't solve the tearing that I was experiencing.

After setting sync to vblank in Compiz, all my tearing problems were solved.

TheBuzzSaw
September 24th, 2010, 08:05 PM
I think sync to vblank in nVidia settings is/was already checked by default. Regardless, it didn't solve the tearing that I was experiencing.

After setting sync to vblank in Compiz, all my tearing problems were solved.

Do you have two different monitors?

mons00n
January 2nd, 2011, 03:31 AM
hey buzzsaw did you ever get this issue resolved? i hate having to boot to windows to watch movies =/

BicyclerBoy
January 2nd, 2011, 04:36 AM
Try not using twin view.

Use separate X screens configuration. This allow independent refresh rates & v sync etc.
This will be a more appropriate config for full screen video like MythTV etc.

TheBuzzSaw
January 2nd, 2011, 11:53 PM
I never fixed it. Disabling one monitor is the only way I know to fix it.

efball3
January 8th, 2011, 02:29 AM
I also had video tearing problems with twinview. I tried lots of ideas from lots of threads. What fixed it was dumping compiz.
I have "mutter --replace" as a startup application. Zero tearing now.

dsevastakis
March 24th, 2011, 07:17 PM
mutter used to work great for me as well.. but 6-7 months ago it started behaving like compiz..so welcome back tearing..:/

it really sucks that i have this problem for 3 years now and still no solution.. i hate switching to windows to watch movies..

i have tried everything from any post i've ever read.. still no luck..

mons00n
March 24th, 2011, 08:14 PM
it really sucks that i have this problem for 3 years now and still no solution.. i hate switching to windows to watch movies..

i have tried everything from any post i've ever read.. still no luck..

The only thing that worked for me was turning off one of the monitors in nVidia settings when watching movies. Was a pain, but worked.

TheBuzzSaw
March 25th, 2011, 02:53 AM
I finally got the tearing to stop by buying a second monitor of the same brand/size/resolution. Now that the desktop has a consistent surface with a matching refresh rate, the tearing is completely gone.

Until Wayland arrives, I don't know that there is much hope for two monitors of different types.

Roasted
October 3rd, 2011, 05:05 AM
Hate to bump this up but I've been having this issue recently too.

Somebody told me recently that I need to have monitors which matching refresh rates. Currently my refresh rates for my two monitors are 59.94 and 60. This, while seemingly insignificant, is said to have a greater impact than we realize... mostly because it sounds like twinview makes the system think you're dealing with one large monitor. Therefore having two separate refresh rates tends to make things wig out a bit. Of course, this is all random bits I've gathered from talking to users in the Ubuntu IRC chat.

I also heard separate X screen support was dropped in 11.10, indicating that twinview is the way to go.

So for now the basic idea of what I'm reading is that you need to have monitors with the same refresh rate when using twinview. That being said, can anybody CONFIRM this for me? I'm very curious to know what the technical definition is of this exact problem. Is it indeed that having slightly different refresh rates when using twinview is the root cause of this problem?

TheBuzzSaw
October 3rd, 2011, 05:13 AM
As you pointed out, Twinview works by operating on both monitors as one giant graphics surface. Wayland and other technologies give each monitor a discrete buffer to work with. So, if your monitors do not match, you will have to fight with the refresh rates. Like I said, I was only able to get rid of tearing by buying two of the same monitor.

BicyclerBoy
October 3rd, 2011, 05:24 AM
The current linux nvidia twinview implementation mandates the refresh rate is the exact same on both monitors.
(read the 30 -40 page nVidia driver readme)

The reported refresh rate could be the problem.
Twinview works by making a dummy meta-mode screen, it seems to use a fictitious refresh rate to get a unique name.

The nVidia driver loads a composite extension that is meant to provide the correct info to composite/desktop managers...

Find the real refresh rate & stick into ccsm ?

Don't use twinview or xinerama.
Don't know how well separate X screens works with Unity desktop as it is built on compiz.


Disabling support for separate X screens in 10.10 makes no sense to me unless wayland in very close to release but even then:
- separate X screens is basic building block of X.
- wayland would have no support in nVidia/AMD drivers.
- twinview supports only 2 screens (badly)
- The real multi-monitor support on nVidia is limited to only quadro pro cards (SLI mosaic)
so would be left with nothing (work properly) except single screen..

Roasted
October 3rd, 2011, 05:36 AM
Hmm, I wonder how far off Wayland is. It's a shame because I don't have the money for another monitor yet I would certainly like to watch videos without tearing. Fortunately my HTPC won't have this issue being the TV is the only 'monitor' on that system. phew...

Can you set refresh rates of monitors or are they hardcoded into them by design from the manufacturer?

Also - setting the refresh rate in compiz did nothing for me. In fact, nothing at all helped. Whether it was sync to vblank, adjusting certain compiz settings, etc... nothing worked at all. :(

Fortunately if I do plan to sit back and watch an entire movie, swapping over to 1 monitor isn't THAT much of a hassle. However, it'd be nice to not have to do that.

BicyclerBoy
October 3rd, 2011, 06:24 AM
You can set the refresh rates to be whatever the monitor will sync to..
But monitors are designed to receive standardised video modes.
The supported modes & sync limits etc are contained in the monitor EDID; a mechanism that has been around since 15 pin Dsub VGA..

Watching video at the incorrect refresh rate is not nice..
50Hz material should not be watched at 60Hz or vice-versa.
Thats another reason why twinview is not good for HTPC.
Small refresh errors will have a judder cadence, very noticeable on high motion.

nVidia VDPAU does not use the vsync blank settings in any config file.
It is always sync to the video frame/field rate.

The sync settings are to do with OpenGL or XVideo display method only.

BTW
the GTX 260 275 285 etc are not very good HTPC cards too much noise/heat not very good VDPAU.
GT430 is the best ATM.

Roasted
October 3rd, 2011, 12:57 PM
You can set the refresh rates to be whatever the monitor will sync to..
But monitors are designed to receive standardised video modes.
The supported modes & sync limits etc are contained in the monitor EDID; a mechanism that has been around since 15 pin Dsub VGA..

Watching video at the incorrect refresh rate is not nice..
50Hz material should not be watched at 60Hz or vice-versa.
Thats another reason why twinview is not good for HTPC.
Small refresh errors will have a judder cadence, very noticeable on high motion.

nVidia VDPAU does not use the vsync blank settings in any config file.
It is always sync to the video frame/field rate.

The sync settings are to do with OpenGL or XVideo display method only.

BTW
the GTX 260 275 285 etc are not very good HTPC cards too much noise/heat not very good VDPAU.
GT430 is the best ATM.

I see. I had no idea twinview was lacking in regard to no tearing support. I do have to wonder, though... why Windows has no tearing issues? I've watched movies in Windows (XP, 7) and had no tearing whatsoever on any player. I assume the Windows setup for dual screen is just different and/or a bit better?

Currently on the HTPC I'm just using the onboard card, which is a Nvidia 6150. It has exhibited no tearing, however I think I may have synced to vblank on that system. I feel like I saw tearing initially until I made that change. I assume that's the curve ball... that the settings work fine until you fire up a 2nd monitor in twinview... which being a HTPC we're talking one monitor so it eliminates that factor. Along with that, with a 6150 not serve its basic functions as a HTPC? I seem to have black bars on the left and right sides I can't get rid of... perhaps pushing the card to display on a 37" screen is a bit too much?

Moving back a bit, let's break it down a little. I need a very, very unbiased answer here. Currently... as of now... would it be safe to say ATI is a better graphics card company to go with in order to avoid twinview tearing on Linux systems? I kept reading about their anti tearing drivers, and the tearing I'm seeing has been continually blamed on limitations of the Nvidia driver.

Does anybody have any further insight? If I would get an ATI card would I likely have the same issues or would I be able to squeak past with twinview and no tearing?

BicyclerBoy
October 3rd, 2011, 08:38 PM
I don't see any tearing with linux/nvidia in > 3yrs on multiple PC setups:
8.04 - 10.04 with 9400GT (dual monitor)
10.04 GT240 (dual monitor)
10.04 - 11.04 9400GT or GTX260


The implementation of twinview in linux is nothing like windows twinview.
Linux nVidia twinview is a hack/work-around to get a windows-like dual monitor desktop in X server.

Historically there was open source/spec xinerama extension for X.
Don't try xinerama as this has no openGL performance.

You don't have to use twinview to have 2, or more, monitors.

I think the AMD multi-monitor desktop support is superior to nVidia.
nVidia only allows proper multi-monitor desktop with quadro pro cards.

But AMD video decode XvBA is very inferior & immature c.f. VDPAU.
AMD drivers have never been as good as nVidia.

Twinview does not cause the tearing...the 3rd party bling composite managers cause the tearing.

The 6150 has some VDPAU support including HD..but the GT220 is considered the minimum good.

If you use XVideo or openGL video playback acceleration then sync-vblank settings are required.

Don't use compiz or the unity desktop or twinview.
You can use 11.04 with the gnome classic desktop with mutter.

Roasted
October 4th, 2011, 01:01 AM
I don't see any tearing with linux/nvidia in > 3yrs on multiple PC setups:
8.04 - 10.04 with 9400GT (dual monitor)
10.04 GT240 (dual monitor)
10.04 - 11.04 9400GT or GTX260


I can't imagine the 9400GT is that different from my 9600GT. That said, I am *EXTREMELY* curious on your video settings and how you do not have video tearing, as I have video tearing quite obviously.

Do you have sync to vblank set in the nvidia-settings menu?
Do you have sync to vblank set in compizconfig-settings-manager?
What about refresh rates? Are they the same on both monitors? Are your monitors different in make/model?
Any other settings you may have?

BicyclerBoy
October 4th, 2011, 04:24 AM
I don't use twinview..
Full screen video with dynamic video modes (50 & 60Hz) & twinview just do not go together..

The sync vblank setting has no effect on VDPAU playback.
There is a setting for openGL & XVideo (for each separate X screen).

ccsm was only installed couple/six months back to help answer some post about compiz..

I don't use ccsm.
I don't use compiz but it works fine..no problem with VDPAU (MythTV) or XVideo test (VLC).

Monitor 1 is DVI DFP 1440x900@60
Monitor 2 is VGA CRT custom modelines for 1080i60, 720p60, 576p50, 480p60. The preferred video mode 1250i50 is not working yet..

Some months back I had a V20 plasma demo..
monitor 2 = hdmi 1080p50, monitor 1 = dvi 1440x900p60..perfect no tearing & no 5Hz euro judder from using 60Hz on 50Hz material.

It was no problem playing full screen 50Hz VDPAU on one screen & 60Hz video on the other with VLC (or 2nd MythTV but is not as easy as it was).

Roasted
October 4th, 2011, 05:20 AM
I'm still not sure I follow how you got to where you're at. Let's say you set up a new install. How exactly do you get to where you're at? What Nvidia settings do you set? I've just never heard of a way to dual screen without using twin view or using separate x screens. Which separate x screens seems to no longer be supported....

BicyclerBoy
October 4th, 2011, 05:41 AM
Well the HTPC setup is still using 10.04 & separate X screens.

I would offer to try a dual monitor on a 11.04 box but that's just a bit tricky right now.

I could offer to try a 11.04/11.10 live CD on the HTPC...
11.04 offers nothing except problems.

The 10.04 ppas have started to dry up but not completely.

I can't believe separate X screens is not supported if X is still the desktop interface. It is inconsequential if unity interface is only on one screen...
Just use gnome classic or one of the myriad other desktops..

The intel netbook with unity 3d/compiz does not have any video tearing..

Roasted
October 4th, 2011, 12:10 PM
Well the HTPC setup is still using 10.04 & separate X screens.

I would offer to try a dual monitor on a 11.04 box but that's just a bit tricky right now.

I could offer to try a 11.04/11.10 live CD on the HTPC...
11.04 offers nothing except problems.

The 10.04 ppas have started to dry up but not completely.

I can't believe separate X screens is not supported if X is still the desktop interface. It is inconsequential if unity interface is only on one screen...
Just use gnome classic or one of the myriad other desktops..

The intel netbook with unity 3d/compiz does not have any video tearing..

Well I tried to use separate X screens in 11.10 and it was acting very strange. I asked in the ubuntu+1 chat and someone had mentioned to me they were dealing with the same thing and that they believe support dropped. They indicated that KDE had already dropped support and right now XFCE is the only thing using separate X screens still.

No idea how true all of this is, but if it is true, then that kind of tanks my chances here. Doesn't it?

BicyclerBoy
October 4th, 2011, 08:41 PM
I don't see how 11.10 or KDE can stop separate X screens. It is a function of the Xorg & X server driver (in my case nVidia). They can stop the menus etc from appearing on screen 2 but so what..

I believe nVidia will not remove twinview or any Xorg functions until the complete re-write for wayland. This is not going to happen soon because where's the payback ?

Can you imagine the fall-out if Ubuntu breaks the existing nVidia & AMD multi-monitor setups just for unity..

You can run the latest kernels with 10.04 or 10.10, there is almost no reason to bother with the 1ikes of 11.04 11.10..

Xfce is used by mythbuntu; reminds me of the horribly inefficient windowsXP menu structure. That will be a last resort.

BicyclerBoy
October 13th, 2011, 03:41 AM
After some expts with HDMI DFP etc..
Ubuntu 11.04 unity/compiz & the nvidia driver do not share their toys in the sandpit..

With single screen (no twinview) video playback (VDPAU) is unusable without installing & configuring compiz (ccsm).

Run
ccsm
- select General/Composite & tick "Unredirect Fullscreen Windows".
- select Utility/Workarounds tick "Legacy Fullscreen Support".

The last one is needed for MythTV fullscreen..

You can fix VDPAU by just disabling composite in xorg.conf but this just makes a complete mess of the desktop..

Roasted
October 13th, 2011, 01:39 PM
After some expts with HDMI DFP etc..
Ubuntu 11.04 unity/compiz & the nvidia driver do not share their toys in the sandpit..

With single screen (no twinview) video playback (VDPAU) is unusable without installing & configuring compiz (ccsm).

Run
ccsm
- select General/Composite & tick "Unredirect Fullscreen Windows".
- select Utility/Workarounds tick "Legacy Fullscreen Support".

The last one is needed for MythTV fullscreen..

You can fix VDPAU by just disabling composite in xorg.conf but this just makes a complete mess of the desktop..

I'm a little confused. On a SINGLE monitor you had video tearing? I thought you had to have two monitors with unbalanced refresh rates to accomplish this? o.O

Speaking of which, I wonder if 11.10 would offer any difference in terms of playback. WIth Unity and Gnome Shell being built on GTK3 and having things run a little more "in sync" I wonder if that would help.

Looking back, when you consider Unity's initial release on GTK2 and Compiz, it really was kind of a hot mess.

BicyclerBoy
October 13th, 2011, 10:28 PM
I made up a demo MythTV box from the i3 office PC with parts from junk bin (nVidia 9400GT, slightly damaged nova-500-t dvb-t).

The 9400GT has VDPAU but low openGL performance.

The video tearing was not exactly what is described by others..
Playing standard H264 1080i 2x adv. de-interlace, scaled to 1280x720...
This was a faint (to real bad) shear line across the screen (horizontal), 1/3 from top with motion panning right & audio pauses every 10 seconds.
There was significant frame dropping..looked terrible compared to my GT240 setup.

The video tearing was observed with VDPAU playback but not with VLC CPU decode.

Possibly a faster GPU may mask/disguise the problem.

The un-redirection of the full screen window from the composite manager is the key.
There has been plenty of discussion about redirection/composite & bad openGL performance with different desktops..

A solution could be using a ubuntu distro/desktop that does not force the use of composite/compiz.

Roasted
October 14th, 2011, 03:12 AM
I'm building a HTPC using an i3 Sandy Bridge processor. Considering it'll have the GPU capability built in with the CPU, I'm wondering if I'll have some good luck here. I talked to another user who used Sandy Bridge with Linux and said it was pretty incredible, so I'm hoping I have that kind of luck.

If you had the issues with an i3 Intel with a Nvidia card, I have to wonder if it's Nvidia's drivers? That's all I've ever used with Linux...

BicyclerBoy
October 14th, 2011, 09:59 PM
This i3 is the cheapest pre-sandybridge..the GPU was so bad the old 9400GT HTPC card was plugged in after couple of hours..

The nVidia forums trail etc reveals there is a bit of "blame game" going on between nVidia, Compiz & Xorg.

I think the i3 sandy should make a good/ideal HTPC. Low power/hi efficiency/small mobo/ low height

There are a few intel bugs with DP/HDMI & 24p output

This is a very impressive ITX for iCPU SNB :
http://www.zotacusa.com/intel-lga-1155-z68-supreme-mini-itx-z68itx-b-e.html

Roasted
October 15th, 2011, 06:17 AM
There are a few intel bugs with DP/HDMI & 24p output


Anything to be concerned about? Are these bugs anything major? I'm curious to what degree they are.



This i3 is the cheapest pre-sandybridge..



The i3 I'm looking at *is* a Sandy Bridge. I was originally looking at a Pentium Dual Core Sandy Bridge but I decided to bump up my budget a few bucks since the i3 Sandy Bridge was mere dollars away.

BicyclerBoy
October 15th, 2011, 09:42 AM
It is not easy trying to find any info about the HD2000/3000 but they must be better than GMA500.

I think the DP/HDMI problems are just bugs in the open source intel driver..

But I think the 23.976p problem is a design flaw by Intel. (extra frame every 40 secs).
There is a bug fix to get 23.97Hz (not perfect).
http://www.anandtech.com/show/4083/the-sandy-bridge-review-intel-core-i7-2600k-i5-2500k-core-i3-2100-tested/7

Does this matter ?
I think 24p format is daft (low temporal resolution) maybe it is possible to output 48p with video card post-processing frame creation..

Roasted
October 15th, 2011, 06:37 PM
It is not easy trying to find any info about the HD2000/3000 but they must be better than GMA500.

I think the DP/HDMI problems are just bugs in the open source intel driver..

But I think the 23.976p problem is a design flaw by Intel. (extra frame every 40 secs).
There is a bug fix to get 23.97Hz (not perfect).
http://www.anandtech.com/show/4083/the-sandy-bridge-review-intel-core-i7-2600k-i5-2500k-core-i3-2100-tested/7

Does this matter ?
I think 24p format is daft (low temporal resolution) maybe it is possible to output 48p with video card post-processing frame creation..

So how noticable is this issue? This makes me think I should slap some older parts together to get me by for now and when Ivy comes out, upgrade to that. I just have a hard time buying into a product that, while it may be good, still isn't quite up to par. After all, I really want a top quality image, so if every 40 seconds there's an offset picture, I'll certainly notice it.

For the time being, is there any graphics card out there that does the job well? Quite honestly I find it hard to believe a standard graphics card wouldn't do the job, as long as it had some decent power and had HDMI out.

That said, can I blindly choose a graphics card to handle this task for the time being? I guess I'm just put off by the video tearing I've had on my home desktop, but I also have two monitors in twinview with slightly mis-matching refresh rates that might have been causing the issue.

Anyway, I really appreciate the insight so far, as I don't know that much about the specifics of a lot of these graphics cards. But if you guys can fire out an opinion on what I should be able to get away with while having a very solid, clear, 1080 image I'd appreciate it that much more.

BicyclerBoy
October 15th, 2011, 08:41 PM
The frame rate error will make a tiny judder with video motion/panning or scrolling credits/tickers..
This effect can be observed by playing 50Hz material on a 60Hz refresh rate monitor. (5Hz judder).

The Intel fix error will make a glitch every 167sec.
Not that noticeable on old DFPs (which were all judder).

The nVidia GT430 is as good/better than anything available.
Some AMD cards get a higher overall score but only due to supporting some very obscure frame cadence detection.
http://www.anandtech.com/show/4380/discrete-htpc-gpus-shootout/16

And with linux most importantly VDPAU is > 3yrs more mature c.f. AMD XvBA via VAAPI.
VDPAU is more feature rich/complete.

Roasted
October 15th, 2011, 10:23 PM
So do you think the ivy CPU will be that much different? All I hear is how great sandy bridge is, then I also run into a lot of google searches saying the same thing you did above.

That said, what makes the nVidia GT430 that great? Would it be any better than my current desktop card which is a 9600 gt?? not only that but are nvidia drivers in Linux that great anyway?

BicyclerBoy
October 15th, 2011, 10:55 PM
Intel are very clever..but don't seem to care about the GPU performance.
But if the 24p problem affects their profits they will fix it.

I have been using nVidia for H264 HD playback for > 3 yrs with 9400GT & GT240.
The nVidia drivers (& MythTV) have been very reliable.
The nVidia graphics drivers are the best of the possible options.

9600GT 9400GT are only feature set A
GT240 & GT430 are feature set C.
The GT240 features (set C) make a big difference. HD playback just looks better & scaling & sharpening are very good for DVD playback.

Telecine detection of film DVD works whereas my marantz DVD player fails.

GT430 GT240 support HD audio over HDMI.
GT430 is lower power & half height.
Only the GT520 & NVS 4200 are feature set D but it is too slow to de-interlace.

A mythical fermi based GT530 or GT540 would be better because the VPU could be (x2) as fast.

Roasted
October 16th, 2011, 12:11 AM
I see. So the generation of graphics cards that I got in my desktop (the 9600GT) is just not that great for video performance in that regard. I bought this card in mid 2008 I believe, which I don't recall seeing GT430 or GTxxx or any kind available around that time.

So now my game plan has shifted significantly. So overall a system with GT430 might actually give me better video 1080 feedback than a Sandy Bridge proc could. Ehh?

I have a dual core AMD Athlon X2 processor sitting around, along with DDR2 RAM, HDD, PSU, and Case. I could just grab a GT430 and a motherboard for it and slap it together and spend far less than I would on an i3 Sandy Bridge setup (because I would need the proc, DDR3 ram, and mobo) and still get a decent box.

How exactly did you come to know this? What features can I look for in the future on, say, a NewEgg.com tech spec sheet to determine if this graphics card is better performing than another? Or is this just a generational thing, whereas the GTxxx are just OVERALL well known to be better than say a 9600GT or 9400GT or whatever else from that time.

BicyclerBoy
October 16th, 2011, 03:06 AM
Spending too much time on the internet is a good way to find out mostly useless information.

The 9600GT video performance was as good as it was in 2008..
The 8400GS & some nVidia IGP were almost as good.
The 9400GT was the best lower power HTPC card but the 9500GT was fast enough to post-process.

(Wikipedia)
The GT2xx family (end 2009) (not GTX2xx) introduced the better VPU.
GT430 Oct 2010
The GT520 (April 2011) has introduced the best VPU to date but...

The modern video card has (2) main functional blocks: openGL core & video bitstream decoder VPU.
The VPU performance is the feature set or PureVideo designation.
The openGL performance is linked to mem bandwidth & clock speed etc.
Old gaming video cards were all openGL performance only.
The GTX580 video decode is likely the same as GT520.

The openGL processor core shaders are used for post decode processing: de-interlacing, scaling, denoise, sharpen & colour-space conversion.

So from a datasheet you could try to compare shader clock & core configuration, not sure if this would help. You would need to be GPU designer to be able to compare the different architectures of AMD, nVidia & Intel.

Roasted
October 16th, 2011, 05:00 AM
Considering the GT520's price is actually very affordable, I might go for that instead of the GT430.

The problem I have now is what other gear to buy. I suppose a low powered dual core proc and mid-range board should do the trick...

BicyclerBoy
October 16th, 2011, 07:49 PM
Don't buy a GT520..
There will certainly be new cards out next months..
So far only GT520 NVS 4200 have VP5/ feature set D..but both of these are non-starters.

VDPAU decode & CPU de-interlace is not feasible due to massive bus traffic except maybe in optimus graphics setup. You need so fast a PC you may as well use the CPU only..

I would guess that a new GT530 would be VP5 (4Kx2K or 3d 60Hz HD) so perfect & future proofed.

Roasted
October 17th, 2011, 05:32 PM
Don't buy a GT520..
There will certainly be new cards out next months..
So far only GT520 NVS 4200 have VP5/ feature set D..but both of these are non-starters.



How does that help me.. now?

I'm likely buying a GT 430 now that I look more into it. The 520 looks to be rock solid for a HTPC setup but the 430 seems to be far more common with what users are talking about. Now I just need to figure out... do I go with a more budget build and get an AM3 combo or should I get a quieter and more power friendly Sandy Bridge? Either way, despite the SB having IGP, I'd much rather have a dedicated GPU such as the 430.

BicyclerBoy
October 17th, 2011, 08:31 PM
It helps by making it harder to make a decision..

I would get the intel CPU & see if the GPU works okay, & have a PCIe x16 slot free.

Check out the B model (GT430).
http://www.anandtech.com/show/4374/computex-2011-zotac-z68-miniitx-motherboards

Roasted
October 19th, 2011, 09:55 PM
I saw that, but @ 220 bucks it's FAR more expensive than getting the board and GPU separately.

BicyclerBoy
October 20th, 2011, 12:33 AM
Yes, Zotac + ITX + iCPU = expensive.

But at least these non-atom ITX solutions with real GPU have started to come out..

Roasted
October 21st, 2011, 06:22 PM
I ended up finding a 50 dollar visa gift card, which pushed my decision that much easier. I ended up getting the i3 2100 3.1ghz, an MSI H61 board, 4gb DDR3 1333, and a GT 440 1gb GDDR5 card.

I think this is overkill for a standard HTPC, but it was hard to justify getting gear that I haven't experienced with a real HTPC setup before. But considering I may rip my collection I decided a little more horsepower couldn't hurt to be safe.

I also re-tested the video tear thing last night with my dual monitor desktop setup and it's definitely true. A single monitor is great. My duals... tearing.

Anyway, appreciate the help you offered through this. I hope somebody else can learn what I learned.

BicyclerBoy
October 21st, 2011, 09:08 PM
To clarify/summarize previous posts.

single screen tearing (VDPAU) caused by compiz/composite redirection
- solve by un-redirect full screen

opengGL tearing
- triple buffering maybe fix
- set refresh rate in composite (twinview) else auto detect.
- set vsync
- composite settings

twinview tearing caused by incorrect refresh rate reporting
- solve by manually setting refresh in composite & above.
- not a flexible fix.

Workable:
-composite workaround settings

Best soln:
non compositing desktop manager
purge compiz
separate X screens, no twinview.
10.04 10.10 work

There is no tearing with openGL or VDPAU if you use Ubuntu 10.04 & separate X screens. This should also apply to Xunbuntu/mythbuntu/Xfce desktop no compiz.


The VDPAU benchmark qvdpautest does not seem to be affected by composite settings maybe because it does not run full screen or it benchmarks reusing a small number of frames.