mini DisplayPort to HDMI problem with image on screen,Mac Pro4.1

Hi Grant,

model and specs of monitor are LG 29WK500 Ultrawide FHD monitor,resolution 2560 x 1080,two HDMI inputs. Rest of the specs can be seen at the link below.

Have had the Mac Pro4.1 from new and still has its original graphics card in it. A Nvidia GeForce GT 120. Two outputs on the card,mini DisplayPort and Dual link DVI. Specs state that maximum digital resolution for the card is 2560 x 1600.

Peter

LG 29 UltraWide FHD Monitor | LG UK

Hi Grant,

many thanks for your time.

Have been in contact with several computer stores and the local Apple Store. Have also been doing some reading on mini DisplayPort,DisplayPort,DVI dual link and HDMI,as I know nothing about them. Its been suggested that I should try to use the DVI output on the card. The DVI output on the card is a dual link one so I would needed to use a DVI dual link cable to HDMI,as suggested in your last post. DVI dual link does support 2560 x 1600 and I would not have to use a adapter if I have read the info about DVI dual link and HDMI 1.4 compatibility right. Also it seem that if a mini DisplayPort is connected to HDMI via a passive adapter,the mini DisplayPort detect this and only outputs 1920 x 1080. Which is the resolution I am getting in the System Display Preferences. So a active adaptor is required. The source of this info is the Wiki articles on the different formats. Also it seems a mini DisplayPort to HDMI cable would work as long as you do not use a adapter. I may have read this wrong so I will have to reread the article. Have you any idea if I got this monitor working with the graphics card properly what resolution I would see and use in the display preferences.

Peter

Hi Grant,

so it would it would seem.

To be honest I have been in contact with Apple,local Apple reseller's and other computer stores and all have given me contradictory suggestions. I may send the monitor back and get one with DisplayPort and HDMI connectors instead. First I will try your suggestion about using a HMDI 1.4 adaptor or a 4K one. Like I said in my previous post,I know nothing about all these different formats. I am sure that some of the things I read maybe in theory are possible but when it comes to real world practical examples do not work. I will post what success I have if any. Thanks for your time.

Peter

Update.

Tried a active mini DisplayPort to HDMI 4k adapter. It did not work.

Contacted Nvidia support regarding the max digital resolution spec for the GT 120 graphics card.

They said the max digital resolution 2560 x 1600 is only available via the dual link DVI-I output. The mini DisplayPort can only output 1920 x 1080.

Looks like I will have to send the monitor back and choose a different one.

I can either get a 27inch display that works at 1920 x 1080 or try a 29inch ultra wide display that uses DVI-I or DVI-D inputs.

Peter

I sent the monitor back and got another 29 inch ultra wide display from LG,this time with DisplayPort,HDMI and DVI-D inputs. Connected the dual link DVI-I output on the GT 120 graphic card to the DVI-D input on the monitor and it worked. Screen looks great. No distortion of image as before. Got the 2560 x 1080 resolution setting in the display preferences for the LG monitor. Nvidia support said that the 2560 x 1080 resolution is only available on the DVI-I output from the card and the DVI-I output will drive a 29 inch ultra wide screen. The mini DisplayPort output on the card will support high resolutions but not the full 2560 x 1080 required by a ultra wide screen.

Peter