MP 6,1 5120x1440 resolution not working

tentacle

macrumors newbie
Original poster
Mar 13, 2020
5
2
Hey there,

I have a late 2013 Mac Pro with 32GB RAM and a 2GB video card. I also have a Dell U4919DW monitor which I've been using on my PC connected with a single HDMI at 5120x1440 no problems at all.

If I connect up the MP via either a DP or an HDMI or both, my option for this resolution is 5120x1440 (low resolution). In that mode the picture is totally distorted and barely readable. It works in a 3840 resolution, but it's noticeably not as crisp as the 5120.

Am I doing something wrong, or is this not supported? I'm genuinely surprised that it doesn't work, but equally it's a 7 year old machine so I don't know if I'm expecting too much.
 

vertical smile

macrumors 601
Sep 23, 2014
4,704
5,772
In my experience, some GPU supported resolutions are missing from the MacOS for some reason.

I had a similar issue where an ultra-wide resolution just wasn't working with my Late 2011 17" MBP when connected to an external monitor. This was only in MacOS, as it was fine with Windows.

I ended up getting it working using some third party software, called SwitchResX. It required to temporarily disable System Integrity Protection (SIP) and I had to manually add the resolution I wanted.

Oh yeah, I could only get it running at 50Hz, but it still looked good.

You may not have to do any custom stuff, as there is a bunch of built-in resolutions that the OS just won't give you access to for some reason. It wasn't hard, but not really straightforward at first.

Maybe someone else can elaborate.

Hopefully you can get a solution without having to do third-part software, but if you can't, check out SwitchResX.
 

h9826790

macrumors G5
Apr 3, 2014
14,263
6,861
Hong Kong
Hey there,

I have a late 2013 Mac Pro with 32GB RAM and a 2GB video card. I also have a Dell U4919DW monitor which I've been using on my PC connected with a single HDMI at 5120x1440 no problems at all.

If I connect up the MP via either a DP or an HDMI or both, my option for this resolution is 5120x1440 (low resolution). In that mode the picture is totally distorted and barely readable. It works in a 3840 resolution, but it's noticeably not as crisp as the 5120.

Am I doing something wrong, or is this not supported? I'm genuinely surprised that it doesn't work, but equally it's a 7 year old machine so I don't know if I'm expecting too much.
What you actually see at this page?
Screenshot 2020-03-14 at 2.52.10 AM.png
 

tentacle

macrumors newbie
Original poster
Mar 13, 2020
5
2
You should select 5120x1440 (low resolution)
Ah - maybe I should have been clearer in my first post: selecting that resolution displays a distorted image which is the reason I asked the question. It's barely legible and it appears to display only half of the total screen estate with the other half hidden off screen with no way to view it. I've taken a couple of pictures of it so you can see what I'm actually seeing:
 

Attachments

Last edited:

chrfr

macrumors G3
Jul 11, 2009
9,704
3,561
Hey there,

I have a late 2013 Mac Pro with 32GB RAM and a 2GB video card. I also have a Dell U4919DW monitor which I've been using on my PC connected with a single HDMI at 5120x1440 no problems at all.

If I connect up the MP via either a DP or an HDMI or both, my option for this resolution is 5120x1440 (low resolution). In that mode the picture is totally distorted and barely readable. It works in a 3840 resolution, but it's noticeably not as crisp as the 5120.

Am I doing something wrong, or is this not supported? I'm genuinely surprised that it doesn't work, but equally it's a 7 year old machine so I don't know if I'm expecting too much.
The 2013 Mac Pro only supports that resolution if you can find one of the very rare dual cable 5k displays, though I'm not sure any were ever actually manufactured. It definitely won't do those resolutions over HDMI. The HDMI port is only HDMI 1.4; it will only do 4k at 30Hz.
Edit: the only dual cable 5k display I can find is the long-discontinued Dell UP2715K.
 

tentacle

macrumors newbie
Original poster
Mar 13, 2020
5
2
The 2013 Mac Pro only supports that resolution if you can find one of the very rare dual cable 5k displays, though I'm not sure any were ever actually manufactured. It definitely won't do those resolutions over HDMI. The HDMI port is only HDMI 1.4; it will only do 4k at 30Hz.
Edit: the only dual cable 5k display I can find is the long-discontinued Dell UP2715K.
Interesting - thank you for the response! I think some of my confusion may come from not really understanding what constitutes 4k or 5k. If the DP would support 4k on a single cable then in my mind it's capable of pushing 3840x2160 pixels for a total of 8,294,400. I'm 'only' looking for 5120x1440 which is 7,372,800. I sort of assumed that a 1440 resolution didn't qualify as a 5k picture? Am I totally wrong about this?
 

h9826790

macrumors G5
Apr 3, 2014
14,263
6,861
Hong Kong
Ah - maybe I should have been clearer in my first post: selecting that resolution displays a distorted image which is the reason I asked the question. It's barely legible and it appears to display only half of the total screen estate with the other half hidden off screen with no way to get to it. I've taken a couple of pictures of it so you can see it:
I see, that make sense now.

It seems the GPU can render it properly (e.g. if you press Command + Shift + 3, it can make a flawless screen capture). However, it can only output max 3840x2160 (as per the W7000 spec).

I understand that your monitor has less pixels than 3840x2160, however, total pixels is just one of the limitation. If your GPU cannot output 5120 horizontal resolution, then pixel count doesn't really matter, it just won't work.

A work around is actually by using two cables. Your monitor has split screen (side by side). Therefore, if you use two cable to make it works like two 2560x1440 monitors (without gap). You should able to utilise all pixels without trouble.

The menu bar won't looks good (I tested this on my 32:9 monitor). However, this should be the best work around at this moment. You can still stretch any windows on the screen, and still looks like a single monitor (especially if you make a 32:9 wallpaper for it). However, full screen mode won't work, but become "half screen mode".
 

tentacle

macrumors newbie
Original poster
Mar 13, 2020
5
2
A work around is actually by using two cables. Your monitor has split screen (side by side). Therefore, if you use two cable to make it works like two 2560x1440 monitors (without gap). You should able to utilise all pixels without trouble.
That's the one!

Thank you - that's an absolutely perfect workaround. I'm surprised that I can't get it to spit out the full 5120 width at once, but using the split screen mode (which I totally forgot existed - d'oh) and turning off the "displays have separate spaces" option in Mission Control gets me close enough. I can live with the slightly odd menu and dock positioning no problem and it's not much harder to switch back to the PC when I need it and the KVM switch all works still.

Really appreciate your help! :)
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.