Question for 7970 users.

[metalnwood]

OK, I have a 6970 with eyefinity and I get screen tearing because I am using dvi mixed with displayport. I only recently found out that the tearing I had was because of this.

 

So, the new asus 7970 lets you use 3 display ports. No problem, that will sove the issue but we are all out of stock for a month over here.

 

 

So, my question is to those who have 7970's and running eyefinity (anyone left?) can you run 2xdvi's and the hdmi port at the same time? This would fix the timing issues and was not available on the 6970.

 

Thanks!

[StageFright]

As far as I know, you have to use atleast one of the display-port to utilize eyefinity. I just upgraded from two 6970's running 3 monitors to two 7970's running 6 monitors. 3 27" in eyefinity and 3 in extended desktop, waiting for my touch screen overlays. Anyway....the dual 7970's has been awesome with 6 monitors....except for DCS A-10. this is the only game I am having issues with. Cant play it for more then a few minutes with out a BSOD or just black screen with no recovery. From what I have read this seems to be a common problem with the 7970's and DCS. I would hold out on the 7970's to make sure either ATI or DCS addresses this issue...until then I'll be pulling my hair out trying to find a work around.

[Kuky]

I have reference board 7970 that has 1x DVI 1x HDMI and 2x miniDP connectors. I have 4 monitors running (one of each connector) and I don't see any tearing. They are connected like this:

 

DVI -> straight to 24" main monitor

HDMI -> adapter to VGA -> 7" touch screen

miniDP -> adapter to VGA -> 8" screen (for MFD)

miniDP -> adapter to VGA -> 8" screen (for MFD)

Edited April 4, 2012 by Kuky

[metalnwood]

Thanks Kuky, I am not sure about when where tearing occurs.

 

I am running eyefinity and I believe it only happens there. It's because 2 monitors are on one clock and another monitor is on another so there is a slight difference

 

 

If you look at this video another guy has shown it, it seems to be common on eyefinity setups when you mix dvi and displayport.

 

That tearline works it's way up the screen very slowly, I measrued it once. I dont remember but it takes a few minutes and it's annoying when panning, banking while pulling a bit of G because the tear can become visible.

 

I have not noticed it in other games, that could be because I run a10 in windowed mode so that I can use helios and export displays. It might not be a problem in fullscreen.

 

I didn't realise the 7970 was still giving DCS such problems, the talk was quiet around here so I thought they may have resolved themselves.

[Kuky]

Do you by any chance use Windows Aero theme? Since you run DCS in windowed mode you should definitely use Aero theme, it might also get rid of tearring since this theme will enable vsync for application that are not running full screen mode and don't have option to turn vsync on (like FC2 for example) so it might help with A-10C (I also run it in windowed mode and I don't get any tearring)

 

EDIT: just tested to make sure I am not making a mistake and I can confirm when I use Aero theme I don't get any tearring... when I use non-Aero theme I do get tearring... but funny thing is on that video I notice that guy is also using Aero theme so I don't know what gives???

Edited April 4, 2012 by Kuky

[metalnwood]

I am using an aero theme as helios and dcs crawl to an ugly halt without it.

 

From my understanding the problem is because I have two screens plugged in to DVI and they run off a clock in the card. The third, as is my only option, is plugged in to a displayport. This is using a different timing clock.

 

The dvi and DP are now not quite in sync, only fractionally out but produce that very slow moving line that gives tearing.

 

I have seen much talk about it and it appears on ATI the only way to fix it is to get an eyefinity 6 card that allows you to plug all monitors in via DP.

 

I see that nvidia have enough clocks onboard to allow the 680 to use hdmi, dvi and dvi. Essentially 3 of the same.

 

I have been thinking about a 680, they seem (nvidia) to run better on all sims, or at least equally. nvidia is better for ati on FSX and anything that uses opengl. It seems that nvidia users are much more easily able to play around with AA settings. On my 3x42" scrrens it's important to have good AA and on some sims it's lacking with ATI but I know nvidia users can get it going.

 

Trouble is nvidia is expensive right now and are pushing around $1k in NZ.

[SV_huMMer]

I am using an aero theme as helios and dcs crawl to an ugly halt without it.

 

From my understanding the problem is because I have two screens plugged in to DVI and they run off a clock in the card. The third, as is my only option, is plugged in to a displayport. This is using a different timing clock.

 

The dvi and DP are now not quite in sync, only fractionally out but produce that very slow moving line that gives tearing.

 

 

From my experience with ATI, and from what I read in their tech docs, the DP clock is used as a primary source for clocking all other display outputs. So I am not entirely sure that different clocks on different display interfaces is an in-built feature of ATI cards.

 

It looks like it somehow matters how your main (primary) monitor is connected. I used to have all sorts of strange problems with eyefinity, when I ran 3 monitors off a 7950, with the primary (main) screen connected to DVI, and the two "extended" ones - DP. I recently changed the wiring so that my main screen is connected via DP, and two others - DVI + DP. Things did get better. I am still having issues with Catalyst presets, can't properly swich between single monitor, extended desktop and Eyefinity group modes, but at least I stopped getting my side monitors all of a sudden become "640x480 Maximum reported resolutuion".

 

I don't have any visible "tearing" in neither of DCS titles (A10C and BS 2), nor in MS FSX, RoF, BoB etc.

[metalnwood]

From what I understand most ati cards so far can only generate 2 dvi compliant signals. Thats why you need at least one active display adaptor for three monitors.

 

The adaptor takes the DP signal and reencodes it to be DVI compliant. A little bit about it is here http://www.facebook.com/note.php?note_id=306881936286

 

For myself and others it means that one or two monitors where their signal path is different, its not generated by the GPU as the others are. Thats the root cause as I understand it.

 

It looks like the 680's can generate 3 dvi signals so that the 2xdvi and HMDI can all work at the same time. That should solve it as well.

 

On the 6970 you cant use those three, only two, i.e. 2xdvi or hdmi and 1xdvi.

[SV_huMMer]

I see your point, are you saying NONE of your current monitors have native DP support?

 

In this case my set up is not a good example, as I have all three monitors supporting DP, and the only reason I am using DVI on one of them is because the 7950 I have has only 2 miniDP outputs.

[metalnwood]

Yes, thats right, none have DP. They are all hdmi.

 

Over at widescreengaming forum there is a large thread about how the 6 eyefinity will solve it if you connect all monitors via DP. In my case they would all use active adaptors but at least the timing should be consistent between them all.

 

Then I think about the nvidia again... argh. lol

[SV_huMMer]

It's true that the efficiency of Eyefinity-based solutions is heavily dependent on how well you can utilize DP connectivity. I was lucky (or wise enough :-)) to first decide on the GPU manufacturer for my new rig, and then choose monitors with native DP support. Not that it solved all Eyefinity problems, but at least I was able to avoid timing issues.

 

We will still have to see the new NVidia GPU performance and convenience in multi-monitor configurations, but from what's available for sale now IMHO ATI has an edge in terms of features in multi-monitor field.