AMD resolution scaling problem

[NirK]

My 980ti is gone while waiting for the 1080, I am currently on a 5870 on my 3440x1440 monitor.

If I set GPU scaling to full screen, I can run 2560x1080 at 60hz, but as soon as I try and run 2560x1080 at 80hz, it will not go full screen and will only scale 1:1 so 2560x1080 is a small box in the centre with black around it. In the GPU scaling option it will just keep going back to 1:1 scaling when I select full screen. I have also tried adding custom resolutions in the registry.

Can anyone tell me how to get 2560x1080 at 80hz working full screen? Just so I can play rocket league at decent FPS until the 1080 comes out?

Thanks

 

[BS Dave]

Are you using a dual dvi cable? You'll need it for more than 60hz I believe

 

[NirK]

Are you using a dual dvi cable? You'll need it for more than 60hz I believe

No its displayport, It will work at 3440x1440 up to 85hz.

But when I set it to 2560x1080, it will scale it to full screen at 60hz, then as soon as I change it to 2560x1080 80hz, it will only work at 1:1 scaling so it is a small rectangle with black around it, it won't let me use 2560x1080 full screen (but it works at 60hz)

I have gone into the registry and added 2560x1080 80hz and it is there on the menu, but it won't fill the screen, it will only full screen at 2560x1080 60hz.

 

[JTrickle]

My old 5850 has a pair of HDMI outlets and a DVI. I don't think display port was invented back then?

Therefore the best I could expect would be 3440x1440 @30Hz. But afaik more often than not depending on card/cable you should usually get 60hz for 16:9 1440p via old school HDMI. [not sure even that is always guaranteed depending on card]

Same as when I connect my 280x/7870 hdmi sockets to my 21:9x1440p monitor. Cant get more than 30hz from HDIM. Need to use a DVI output + DVI cable to get 60.

 

[Phixsator]

the 5870 only has DP 1.1 which limits its bandwidth to 8,64 Gbit/s. 3440x1440@60hz 8 bit color depth requires 8.92 Gbit/s. If possible you could lower the Color depth to 6 bit which could make 3440x144@60hz0 possible over DP 1.1

And 5850 does come with a DP. The one im currently on has one, its from sapphire and its powering my Dell until the new cards gets released.

 

[JTrickle]

Interesting. I probably paid bottom dollar for mine at launch

 

[NirK]

the 5870 only has DP 1.1 which limits its bandwidth to 8,64 Gbit/s. 3440x1440@60hz 8 bit color depth requires 8.92 Gbit/s. If possible you could lower the Color depth to 6 bit which could make 3440x144@60hz0 possible over DP 1.1

And 5850 does come with a DP. The one im currently on has one, its from sapphire and its powering my Dell until the new cards gets released.

Hmm just did some research and the 5870 is DP 1.1 which has max bandwidth 8.64

3440x1440 60hz 8.9

3440x1440 80hz 11.9

So I am not sure how it has even been working at 3440x1440 80hz.

On the AMD control panel it says 3440x1440 85hz high color 32bit

...........................................

Actually it is 6 bit color depth, but AMD control panel not reporting correctly.