Can't force laptop to do 4k @ 60hz over dp 1.2?

[Skylar1146]

Hello everyone, I have an alienware 13 laptop with intel hd 4400 and an nvidia gtx 860m. I am trying to use the mini displayport 1.2 cable on my laptop to the full size dp on my monitor. I cannot get it to do above 30hz @4k though.

The problem is that the external monitor is using the intel hd and not nvidia. There is no option to force use nvidia gpu only in bios. I did set it the global graphics processor to the nvidia in the control panel. I tried using CRU to force set 4k@ 60hz but to no avail. The monitor is indeed capable of 60hz, it is the acer cb280hk. Any ideas? Thanks, Skylar

 

[ak47jar3d]

It's probably the cable being used. If the cable is a converter, it be reduced to 30hz.

 

[Skylar1146]

It's probably the cable being used. If the cable is a converter, it be reduced to 30hz.

It's mini displayport 1.2 to full displayport. Aka thunderbolt. Not a converter

 

[ak47jar3d]

I would verify that MST is enabled in the monitor settings. More often then not, it will be enabled automatically.

 

[Skylar1146]

I would verify that MST is enabled in the monitor settings. More often then not, it will be enabled automatically.

Yeah i've devled through the settings, I have it set up as should. Im almost positive the problem is it's setting the display adapter for the monitor to use intel hd, which cant support 4k 60hz. I need it to use the nvidia graphics.

 

[ak47jar3d]

Trying disabling intergrated graphics in the device manager. It might work. The ports on the laptop should be using dedicated graphics anyways, but I seen weirder things happen.

 

[Skylar1146]

Trying disabling intergrated graphics in the device manager. It might work. The ports on the laptop should be using dedicated graphics anyways, but I seen weirder things happen.

Hm so I tried that, and restarted. It shows im using the dgpu, but it won't detect the other monitor. Any ideas?

 

[ak47jar3d]

Give me the exact model number of your laptop so I can see if there is a technical reason why it's not happening.

 

[Skylar1146]

Give me the exact model number of your laptop so I can see if there is a technical reason why it's not happening.

It is the second generation alienware 13. It has an 860m, and an i5-4210u with intel hd 4400. They don't have my model on dells site anymore as their is a newer generation out. Also when disabling intel hd I do not have access to the nvidia control panel's display tab. Here is the link to the newer model http://www.dell.com/us/p/alienware-13-r2/pd

 

[ak47jar3d]

I have good and bad news. I was able to determine the problem. According to dell, the 860m is a render only gpu. Meaning the intergrated graphics are responsible for displaying the final image. To paraphrase, it won't be possible for you to use your laptop at 4k 60 hertz. It's very unusual setup for the alienware line of laptops that unto this moment I was completely unaware of.

 

[Skylar1146]

I have good and bad news. I was able to determine the problem. According to dell, the 860m is a render only gpu. Meaning the intergrated graphics are responsible for displaying the final image. To paraphrase, it won't be possible for you to use your laptop at 4k 60 hertz. It's very unusual setup for the alienware line of laptops that unto this moment I was completely unaware of.

Wow that's pretty dissapointing. It may have to do with the fact alienware wants you to buy their graphics amplifier to use a desktop gpu. I don't know why they would even use displayport on the laptop then. Thanks so much for your help!