How does 1440p scaling look on 4K monitors?

whitedragon101

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I am thinking of getting a 27" 4K monitor but I don't want to run it at native (I'm not sure if anyone does). 1440p seems to be the sweet spot for 27". How does OS X 1440p scaling look on a 4k monitor?
 

hfg

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Dec 1, 2006
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I have the Dell P2715Q and I think 1440 scaling looks fantastic on it ... however, I find for my eyesight, that for stuff like reading these forums, I prefer the Retina 1080p so that I can lean back in my chair with a track pad and easily read all the text. YMMV
 

hfg

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My P2715Q running great at 60Hz on a cMacPro with GTX 680 over the DisplayPort interface. They may be on sale at times, but probably more than $300! :)

From "AboutThisMac" as I am typing this on it:

DELL P2715Q:
Resolution: 1920 x 1080 @ 60Hz (1080p)
Pixel Depth: 32-Bit Color (ARGB8888)
Display Serial Number: xxxxxxxxxxxxxxx
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Connection Type: DisplayPort
Television: Yes
 

Hdub32

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Feb 19, 2015
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Hdub32

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- Well, 1920x1080 HiDPI is still a 4K resolution. The interface elements are just 4 times as large as they would be on the standard 3840x2160.
Ahh I see. So 30hz would still run like crap I suppose
 

VirtualRain

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whitedragon101

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VirtualRain

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Thank you that is very helpful. The scaled 4k does look better than the native 1440p.
I guess historically, running anything other than native resolution on an LCD display looked horrible, but with Apple's retina scaling people need to unlearn that. It's no longer the case.

Fonts are rasterized, not bitmaps so they will always look sharper with more pixels to render them. And all retina-aware apps also provide double-resolution bitmap graphics to ensure ultra sharp images. When you combine those pixel-doubled images with Apple's scaling algorithm that renders the desktop at double the selected resolution and then down-samples it, of course you're going to get a sharper result.
 
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whitedragon101

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I guess historically, running anything other than native resolution on an LCD display looked horrible, but with Apple's retina scaling people need to unlearn that. It's no longer the case.

Fonts are rasterized, not bitmaps so they will always look sharper with more pixels to render them. And all retina-aware apps also provide double-resolution bitmap graphics to ensure ultra sharp images. When you combine those pixel-doubled images with Apple's scaling algorithm that renders the desktop at double the selected resolution and then down-samples it, of course you're going to get a sharper result.
Thanks for the help. I have returned here as you seem to know all about running 4K.

I was planning on running the scaled 1440p @60hz on a 4K monitor on a current gen (or maybe wait for refresh) 15" rMBP. Is this possible with the latest version of Yosemite. I have seen loads of posts of people using hacks and switchresx and having issues. Some even saying upgrading to the latest version of Yosemite means their scaling options disappeared. I thought it was plug and play now on the current gen but now I'm not sure. So I was hoping you would have the answer :

Can you run a 4K monitor scaled to 1440p (using the apple way of downsampling 5120x2880 for sharpness) at 60hz without hacks simply by plugging the monitor in and selecting the 1440p scale in the settings?
(the apple site doesn't seem to mention what scaled resolutions are supported or if scaling effects the refresh rate i.e does scaling reduce it to 30hz)
 

VirtualRain

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Aug 1, 2008
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Thanks for the help. I have returned here as you seem to know all about running 4K.

I was planning on running the scaled 1440p @60hz on a 4K monitor on a current gen (or maybe wait for refresh) 15" rMBP. Is this possible with the latest version of Yosemite. I have seen loads of posts of people using hacks and switchresx and having issues. Some even saying upgrading to the latest version of Yosemite means their scaling options disappeared. I thought it was plug and play now on the current gen but now I'm not sure. So I was hoping you would have the answer :

Can you run a 4K monitor scaled to 1440p (using the apple way of downsampling 5120x2880 for sharpness) at 60hz without hacks simply by plugging the monitor in and selecting the 1440p scale in the settings?
(the apple site doesn't seem to mention what scaled resolutions are supported or if scaling effects the refresh rate i.e does scaling reduce it to 30hz)

There is a lot of confusion, primarily because some people are trying to use 4K at 60Hz on older MacBooks or older OS X installs. I believe folks in the Dell P2415Q and P2417Q thread are running dual 4K displays at 60Hz off recent 15" rMBP without issue on 10.10.3. Double check in that thread with someone who has your config. I have a Mac Pro so I'm no authority on what works on various models of Macs. But I will say that those Dell displays are currently the best choice.

As for scaling and running 2560x1440 HiDPI, if you can run 4K at 60Hz, you should have no trouble... The scaling options should appear automatically in Display Preferances.
 

Naio

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Apr 2, 2015
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How is it possible to run a 4K external display in 5K scaled? I thought current cables didn't have enough bandwidth for 5K @ 60 Hz.
 

VirtualRain

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Aug 1, 2008
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Vancouver, BC
How is it possible to run a 4K external display in 5K scaled? I thought current cables didn't have enough bandwidth for 5K @ 60 Hz.
Don't confuse Apple's scaling algorithm with native display resolution.

When Apple scales 2560x1440 HiDPI to a 4K display, it first renders the desktop in the GPU frame buffer at double the resolution (5120x2880 or 5K) and then down samples it to the 4K display resolution.

We're not talking about Displays with 5K native resolution here. As you point out, those require a pair of DP1.2 connections to drive properly.
 
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Naio

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Apr 2, 2015
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Don't confuse Apple's scaling algorithm with native display resolution.

When Apple scales 2560x1440 HiDPI to a 4K display, it first renders the desktop in the GPU frame buffer at double the resolution (5120x2880 or 5K) and then down samples it to the 4K display resolution.

We're not talking about Displays with 5K native resolution here. As you point out, those require a pair of DP1.2 connections to drive properly.
I probably wasn't clear in what I was trying to ask, but I think I understand now. Thanks.
 

whitedragon101

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Sep 11, 2008
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There is a lot of confusion, primarily because some people are trying to use 4K at 60Hz on older MacBooks or older OS X installs. I believe folks in the Dell P2415Q and P2417Q thread are running dual 4K displays at 60Hz off recent 15" rMBP without issue on 10.10.3. Double check in that thread with someone who has your config. I have a Mac Pro so I'm no authority on what works on various models of Macs. But I will say that those Dell displays are currently the best choice.

As for scaling and running 2560x1440 HiDPI, if you can run 4K at 60Hz, you should have no trouble... The scaling options should appear automatically in Display Preferances.
Thanks.

If this display lives up to the hype I am hoping I will get this one. Should be out Q3 this year.

Its a 27" IPS 4K gaming monitor with g-sync. Their existing 4K (non g-sync) is 100% sRGB so I'm hoping this will be too. The perfect work and play monitor I am hoping. Connect the PC for games and the Mac for work :)

http://rog.asus.com/393642015/gaming-monitors/ces-2015-rog-swift-pg27aq-27-inch-4k-lcd-with-gsync/
https://www.youtube.com/watch?v=1QiQ6y1jJ5A
 

dagamer34

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May 1, 2007
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Houston, TX
There is a lot of confusion, primarily because some people are trying to use 4K at 60Hz on older MacBooks or older OS X installs. I believe folks in the Dell P2415Q and P2417Q thread are running dual 4K displays at 60Hz off recent 15" rMBP without issue on 10.10.3. Double check in that thread with someone who has your config. I have a Mac Pro so I'm no authority on what works on various models of Macs. But I will say that those Dell displays are currently the best choice.

As for scaling and running 2560x1440 HiDPI, if you can run 4K at 60Hz, you should have no trouble... The scaling options should appear automatically in Display Preferances.
It's possible, but the mere plugging in of the 2nd monitor causes the fan to ramp up to fairly audible levels. You're stressing the GPU more than you really should in that configuration if used for an extended period of time.
 

bigpoppamac31

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Aug 16, 2007
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Canada
I know this is an old thread but I'm wondering the same thing. I'm looking to get an external monitor for my 2014 rMBP 13" but it only does 4K at 30hz. If I use a 4K monitor at something like 1440p will it look okay?
 

MrX8503

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Sep 19, 2010
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I know this is an old thread but I'm wondering the same thing. I'm looking to get an external monitor for my 2014 rMBP 13" but it only does 4K at 30hz. If I use a 4K monitor at something like 1440p will it look okay?
It'll look ok, but you're still limited to 30hz, which is really laggy.