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whitedragon101

macrumors 65816
Original poster
Sep 11, 2008
1,307
304
I could have sworn I read Apple had updated support for 4K monitors so that you can run a 4K monitor at several scaled resolutions including 1440p using the normal retina scaling algorithm where it renders double the res then samples down to remain sharp.

But I have just googled OS X 4K scaling and I am getting rather conflicting information.

Can the current 15" rMBP on the latest OSX run a 4K monitor scaled to 1440p @60hz?
 
Last edited:

campyguy

macrumors 68040
Mar 21, 2014
3,413
954
Thats not up to date. Apple have since posted this :
https://support.apple.com/en-gb/HT202856

Which says
MacBook Pro (Retina, 15-inch, Mid 2014)
can run a 4K display at 60hz without needing MST

However they don't mention scaling support or if scaling limits the refresh rate.
That "list" means nothing, to me at least - no offense intended. My Late-2013 rMBP has two Dell P2715 4k displays connected to it - I can run them @4k and @60Hz at the same time(plus the internal display), but they're not on that "list", out of the box, no tweaking. IOW, take that "list" with a grain of salt.

I've used an EDID hack and a 3rd-party Preference Pane to get the most out of both displays, to be fair. But, IOW, yes, a 15 inch rMBP can be used to run one or two scaled 1440p displays at 60Hz.
 

whitedragon101

macrumors 65816
Original poster
Sep 11, 2008
1,307
304
That "list" means nothing, to me at least - no offense intended. My Late-2013 rMBP has two Dell P2715 4k displays connected to it - I can run them @4k and @60Hz at the same time(plus the internal display), but they're not on that "list", out of the box, no tweaking. IOW, take that "list" with a grain of salt.

I've used an EDID hack and a 3rd-party Preference Pane to get the most out of both displays, to be fair. But, IOW, yes, a 15 inch rMBP can be used to run one or two scaled 1440p displays at 60Hz.

Thanks. When I search about this I get many stories like yours about having to use hacks and tricks to get things working. I am hoping this is just for laptops not on Apples list.

Is the current rMBP 15" plug and play for 4K scaled to 1440p @ 60hz without hacks?


ps
Quite amazing you can drive 2 4K displays at 60hz with 1440p scaling on a laptop with integrated graphics. How is the performance with 1 vs 2? Any stuttering?
 
Last edited:

campyguy

macrumors 68040
Mar 21, 2014
3,413
954
Thanks. When I search about this I get many stories like yours about having to use hacks and tricks to get things working. I am hoping this is just for laptops not on Apples list.

Is the current rMBP 15" plug and play for 4K scaled to 1440p @ 60hz without hacks?


ps
Quite amazing you can drive 2 4K displays at 60hz with 1440p scaling on a laptop with integrated graphics. How is the performance with 1 vs 2? Any stuttering?
Two bits, although I'm still happy with my displays!

First, the use of the word "hack" is a end-around to get unsupported-by-Apple and/or unsupported-by-vendor 3-party (non-Apple) displays "optimized" for a particular system-display combo - the EDID hack is only one of several means to create a file that allows a Mac, Linux, or Windows PC to communicate with a display that is not fully supported on an OS platform. The "hack" that I used created a display override directory file - which includes the SN and other data specific to my display. These hacks have been used for years, and I first used them on Windows PCs several years ago - IMHO because display manufacturers DO NOT write drivers and other display-specific software for their displays and/or for all platforms.

And, yes, it's saddening to have to resort to get some really cool toys on our desks and laps. :(

These overrides help - in some instances, but not in all instances - a PC communicate with a display to "find out" what that that display is capable of. The override process helped my rMBP immensely, but didn't do a thing for my 2012 Mini Server; my rMBP is connected by mDP>DP to both displays and my Mini is connected by mDP>mDP to one of the two displays, and I actually get more pixels and better display appearance on my Mini without an override in place.

Also, I view SwitchResX as an "override" utility for displays, and IMHO with the advances of 10.10.3 this utility is not necessarily needed anymore to get the most out of my Dells, but it's now become a very convenient utility to layout my workspaces - my two Dells are on arms and I move them around to suit my workflow, and SwitchResX provides the ability to create and save workspaces. Nifty, that. If you view SwitchResX (and other utilities like it) as a means to better "drive" and/or customize a display, because (in my case) Dell didn't - it's easier to get one's head around than by calling it a hack.

Keep in mind that Apple has included several overrides with the stock OS install (System>Library>Displays>Overrides) - most display models have it's own special set of capabilities, and it's up to Apple and display makers to provide more/better sets of overrides, or, in my words "instruction sets".

And, to clarify, my rMBP has the discrete Nvidia 750M GPU - which drives all 3 displays (both Dells and the internal display), all at up to maximum resolution, and all at up to 60Hz. Given the power of the newer integrated GPUs and that all of the 15" rMBPs have both TB2 and 16GB of RAM, I see no reason for the newer laptops to be as capable as mine; there is at least one poster in the P2715Q thread that was driving a widescreen LG TB display and a daisychained P2715Q at full resolution and at 60Hz - and that was before 10.10.3 came out...

I still have a bit of experimenting to do with my layout, but I have to wait until an order from Amazon comes in next week...
 

trms23

macrumors newbie
Oct 19, 2015
10
0
Thanks for your answers. I know that Late 2013 models and later can drive 4k display.

Anyways, I have this graphic card in my macbook pro early 2013:
NVIDIA GeForce GT 650M

The specs say it can only drive a 4k display at 30Hz, but how does it look like on the scaled 1440p resolution for a 4k display (30 or 60 Hz) ?
Thanks!
 

Phil A.

Moderator
Staff member
Apr 2, 2006
5,723
2,890
Shropshire, UK
I run a 4K monitor at 1440 retina scaling on my 2014 15" (via DisplayPort at 60hz) and it works brilliantly - no tweaks, hacks or anything else needed. However, it won't do retina scaling via HDMI (just full res, 1080p and low res scaled modes that look horrible) and it only supports 30hz over hdmi

It's an AOC monitor
 

trms23

macrumors newbie
Oct 19, 2015
10
0
I run a 4K monitor at 1440 retina scaling on my 2014 15" (via DisplayPort at 60hz) and it works brilliantly - no tweaks, hacks or anything else needed. However, it won't do retina scaling via HDMI (just full res, 1080p and low res scaled modes that look horrible) and it only supports 30hz over hdmi

It's an AOC monitor

Yep. I know that. But has anyone the exact as mentioned above.
Macbook Early 2013
 

Samuelsan2001

macrumors 604
Oct 24, 2013
7,730
2,151
Thanks for your answers. I know that Late 2013 models and later can drive 4k display.

Anyways, I have this graphic card in my macbook pro early 2013:
NVIDIA GeForce GT 650M

The specs say it can only drive a 4k display at 30Hz, but how does it look like on the scaled 1440p resolution for a 4k display (30 or 60 Hz) ?
Thanks!

It's not the graphics card that is the issue for your mac @ 60Hz it's the bandwidth on your thunderbolt port, late 2013 onwards have thunderbolt 2 over the thunderbolt 1 standard in your mac and that is why they can run @60hz and your one can't.
 

trms23

macrumors newbie
Oct 19, 2015
10
0
It's not the graphics card that is the issue for your mac @ 60Hz it's the bandwidth on your thunderbolt port, late 2013 onwards have thunderbolt 2 over the thunderbolt 1 standard in your mac and that is why they can run @60hz and your one can't.
Thanks I've understood. So even the scaled 1440p can't be driven az 60Hz?
 

576316

macrumors 601
May 19, 2011
4,056
2,556
I've been told there's no way I'd get my mid-2012 15" Retina MacBook Pro to display 4K at 60Hz. Is that a fact? Looking into getting a 144Hz 1440p monitor instead, as there's no way I'll be able to afford a new Mac any time soon.
 
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