Second 1440p display possible with Display Port to DVI adapter?

[Blue_Ocean]

I currently am running 2 monitors off my 660ti in Yosemite (having problems with Clover so no El Capitan yet): a Dell U2412M running at 1920x1200 via DVI, and a Dell U2515H running at 1440p via Display Port.

My 660ti has 2 DVI ports (one digital, one analog), one Display Port and one HDMI port. I want to upgrade my older monitor to the 1440p U2515H but this particular monitor only has HDMI, Display Port and Mini Display Port inputs.

My card supports 1440p via HDMI but I have read on the forums that 1440p is only possible in OSX via Display Port. So my question is, if I get a Display Port to DVI-D adapter, could I run the second monitor in 1440p? I obviously don't want to buy it and then find out it won't work in OS X.

Alternatively, the monitor supports Display Port daisy-chaining, so could I run 2 monitors off the single Display Port on my graphics card that way?

Thanks!

 

[Delish]

1440p works fine with dual monitors on my 670 GTX or AMD 7950 with DVI(dual link) and DP.

Only think to be aware of is some (older) card have a single link DVI port, that will only give 1920x1200.

 

[Fl0r!an]

I have a U2515H, too, and it runs fine on either HDMI or DP port.

A DVI to DP adapter (this is what you'd need connect the U2515H to a DVI port) doesn't exist. DP to DVI is the wrong direction!

Daisy Chaining doesn't work in OS X, Apple didn't implement MST.

 

[Blue_Ocean]

I have a U2515H, too, and it runs fine on either HDMI or DP port.

Great! Then I should be able to keep one connected to the DP and the new one to the HDMI, both at 1440p.

 

[Fl0r!an]

Since you already have one of those U2515H's, just go ahead and try if it works properly on HDMI on your setup.

 

[Blue_Ocean]

Since you already have one of those U2515H's, just go ahead and try if it works properly on HDMI on your setup.

For some reason I only thought of that just a few minutes before you posted this

I just tried HDMI whilst leaving the 2412 plugged into the DVI port. It maxes out at 2048x1152 resolution for some reason. I used both an old HDMI cable, and a newer one that is 'high speed with ethernet'. I'm not sure exactly which version that refers to, but according to Wikipedia, ethernet was only introduced in HDMI 1.4 which means it should support up to 4k.

The 660ti should support 1440p over HDMI according to its specs, so does this mean it's an OSX issue?

 

[Fl0r!an]

That's strange... I'm driving my U2515H @1440p via HDMI just in this moment (hooked up to my R9 280).
I'll swap in a NVIDIA card (GTX 660) later and see what happens. Maybe NVIDIA WebDrivers will help?

 

[Blue_Ocean]

That's strange... I'm driving my U2515H @1440p via HDMI just in this moment (hooked up to my R9 280).
I'll swap in a NVIDIA card (GTX 660) later and see what happens. Maybe NVIDIA WebDrivers will help?

I'm using the web drivers already actually because I was having issues with the second display staying black with the default OS X driver. I will try to see what happens with HDMI in Windows in a while just to make sure it's definitely OS X related.

Edit: 1440p works with HDMI in Windows no problem so it's definitely down to OS X. That's what I heard from Toleda in another thread so I'm actually surprised it works for you.

 

[Fl0r!an]

I didn't swap cards yet because of some issues with my new Skylake build.

However I did some quick experiments with my AMD graphics: Without injection (that's what I usually use) I'm getting proper 1440p on my HDMI port.
With injection it's limited to 1080p like your NVIDIA.

You could search for patches removing the pixel clock limit, never did something like that myself, but I guess it might help.

 

[Blue_Ocean]

I didn't swap cards yet because of some issues with my new Skylake build.

However I did some quick experiments with my AMD graphics: Without injection (that's what I usually use) I'm getting proper 1440p on my HDMI port.
With injection it's limited to 1080p like your NVIDIA.

You could search for patches removing the pixel clock limit, never did something like that myself, but I guess it might help.

I don't exactly know what you mean by injection - a specific kext or something?

In any case, I'll survive for the time being I guess but I'll keep an eye out to see if there are any fixes. My plan is to upgrade my graphics card once the nVidia Pascal cards are out this year so I'll get one with multiple Display Ports eventually.