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rMB + Dell P2415Q

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kennethkryger

macrumors newbie
Original poster
Jun 17, 2015
2
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I've been using a 24" monitor at 1920 x 1080 for years now on Windows and the size of the screen and text fits perfectly. I'm mainly using it for mail, web, documents and development.

I'm considering buying the new MacBook and a Dell P2415Q (4K) hoping to get a retina look and feel on the external monitor (I've just love the crystal clear text on my iPhone and iPad - and also on the MacBook that I've tried a few times in Apple Stores) - ie. I want crystal clear text rendering on the Dell monitor.

What I think I'm asking for is using HiDPI on the Dell - ie. having the same amount of "stuff" on the 4K screen as on my current HD (1920 x 1080) screen? But having the text be ultra sharp...

Is this possible using with the new MacBook?

Sorry if the answer to this can be found elsewhere in the forum - I've been searching like crazy for this... If so, please just point me in the right direction...
 
One limitation is going to be that the MacBook will only drive that display at 30hz which may or may not be acceptable to you. That limitation is from the hdmi port - I'm not yet clear whether the chipset will do 4k/60hz via display port when an adapter is available. Apple's own literature is somewhat ambiguous here as well. https://support.apple.com/en-us/HT202856

I suspect that as the MacBook is not included in the list of compatible devices via 60hz SST that it is not capable.

That said, what you want might be possible if you choose 1920x1080 as the output resolution, as that will no incur the overhead of having to scale up the content as the computer must do for no integer conversions, as 1920x1080 is exactly 1/4 of the Dell's 4k resolution. Interesting to find out if it will work or not! I'd like to know as well. I can try with my own p2715q later this week if you like.
 
It'll be possible, but only at 30 Hz, which doesn't offer a smooth enough experience in my opinion.
 
If do you want to output 4K at 60Hz, any of the other retina Macs now on sale will do that. If you want an rMB to do 4K at 60Hz, then that's one case when you're definitely best to wait for SkyLake (Skylake most likely will do 60Hz, and I have a feeling Intel has already said so)
 
Wait a minute. If he only wants to output 1080p from the MacBook, why shouldn't that work at 60hz? The display will just render that resolution using 4 pixels per point, just like an iOS device. Not sure it will work, but in theory it should.

Where you would run into problems is if you wanted to run some higher 'virtual' resolution that was not an exact integer multiple. This is how the retina MacBook/MacBook Pro screens work under most situations. The Pro's have a 'default' value that is exactly an integer multiple, so there is no processing overhead. If you choose the 'more space' options, it must upscale the image to some larger resolution, then extract the non-integer resolution from that, causing you overhead. The MacBook can't do this on a 4k display, because it doesn't have the power to render resolutions higher than 4k from which to extract some non-integer resolution. But at 1920x1080 there should be no overhead at all, and so long as you are ok with that real estate, it should work.
 
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I've just tried it, connecting my 1.2ghz rMB to my Dell UP2414Q (4K). While I agree with zhenya, and I would have expected 1920x1080 to work, oddly enough it doesn't. The Displays panel offers 24z, 25z, and 30z (from memory it doesn't usually offer anything). It defaults to 1920x1080, 30hz.
SwitchresX might offer more choices possibly.
 
My other thought on it is that if you run the big screen most of the time, which it sounds like you might from the original post, wouldn't a 13" rMBP be better? Then you can have a port dedicated to it, and also a gruntier graphics card to cope with that much dual screening.
 
I've just bought a P2715Q to go with my MacBook, and I'm selling on my old 27" Apple Display. I'm using Apple's HDMI adapter and here's what I get...

By default System Preferences will give you 1920x1080 (HiDPI) - this gives you the "retina" experience, but it is only at 30hz. From using it for the last hour I find this just about acceptable for office/web-type tasks (I'm a programmer so mostly type).

The only other option by default is the full 3840x2160 resolution - again at 30hz.

I'm hoping that when somebody releases a USB-C to DisplayPort adapter I'll be able to connect it up that way and then be able to get 60hz.

I've then used SwitchResX to set up two custom resolutions. Obviously these are scaled, but comparing the quality of the output to my 27" Apple Display, they are incredibly similar (i.e. still very crisp and clear). These can run at higher refresh rates over HDMI...
  • 2560x1440 @ 62hz - the same as my old Apple Display
  • 2880x1620 @ 50hz - a custom resolution to give me more real estate
I'm currently running on 2880x1620 and it seems fine (perfect for me at 50hz), but I'm sure I'll switch down to 1920x1080 HiDPI now and again too depending on what I'm doing.

Hope that helps! :)
 
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I have a P2715Q as well and the 2560x1440 looks horrible over HDMI. Text is pixelated and unclear. When looking at System Report I can see that the rMB thinks it is a TV. I have tried a couple of scripts to force RGB but it does not help. I am surprised how horrible the display look compared to my MBA and Thunderbolt. I am hoping a HUB+ and a mini DP will resolve this.
 
zhenya said:
One limitation is going to be that the MacBook will only drive that display at 30hz which may or may not be acceptable to you. That limitation is from the hdmi port - I'm not yet clear whether the chipset will do 4k/60hz via display port when an adapter is available. Apple's own literature is somewhat ambiguous here as well. https://support.apple.com/en-us/HT202856

I suspect that as the MacBook is not included in the list of compatible devices via 60hz SST that it is not capable.

That said, what you want might be possible if you choose 1920x1080 as the output resolution, as that will no incur the overhead of having to scale up the content as the computer must do for no integer conversions, as 1920x1080 is exactly 1/4 of the Dell's 4k resolution. Interesting to find out if it will work or not! I'd like to know as well. I can try with my own p2715q later this week if you like.
Click to expand...
Hey saw you respond to another post with a similar question, I have a mid 15 inch rMacbook Pro with the Nvidia 750M 2GB GPU will I be able to run the full 4k resolution 60hz with a Dell P2715Q, I just ordered the monitor few days ago then some people have reported that it doesn't work at 60hz through a mini displayport to Displayport? Thanks in advance
 
Nueve said:
Hey saw you respond to another post with a similar question, I have a mid 15 inch rMacbook Pro with the Nvidia 750M 2GB GPU will I be able to run the full 4k resolution 60hz with a Dell P2715Q, I just ordered the monitor few days ago then some people have reported that it doesn't work at 60hz through a mini displayport to Displayport? Thanks in advance
Click to expand...

I responded in the other thread as well. Can you clarify exactly which computer you have? What screen size and year?
 
zhenya said:
I responded in the other thread as well. Can you clarify exactly which computer you have? What screen size and year?
Click to expand...
mid 2014 15" inch Retina Macbook Pro 2.5GHz 512 SSD with integrated Nvidia 750m 2gb, yeah I thought I had not quoted you on the other post, you answered my question as of right now I will just refuse the package and wait a few months to see if it works at 60hz through mini dp to dp. Thanks
 
Well, after working with my P2715Q for a couple of days on actual work my opinions have changed...

While I thought 30hz would be OK initially - turns out it gave me a headache. The mouse pointer moving jaggedly across the screen got annoying very quickly. I also thought I would be OK with 1920x1080 (HiDPI) - but I was missing the screen real estate offered by my old Apple Display (2560x1440).

For me these were two major issues, and I decided against trying to run 4K from the MacBook. Really a 5K display is what I need - i.e. running 2560x1440 at HiDPI - and that just isn't possible with the MacBook (and you could say its not really the target market of the machine).

For the next day I ran the display at a scaled resolution of 2560x1440 which I was almost happy with - but it wasn't as good as my initial impressions and I didn't actually find it as clear/sharp as my old Apple Display after all.

I figured if I couldn't run 4K properly then it would be silly to stick with a 4K display running a low quality scaled resolution, and that I'd rather get a decent quality 2K screen and have more screen real estate. So, thanks to Amazon's great returns policy, I'm now going to return the P2715Q.

I've replaced it with a U2715H which I've been using today and its absolutely fantastic - it actually is clearer/sharper than my old Apple Display was. It was also cheaper and has a much more modern design than the P2715Q had with a slim bezel. :)
 
nickday said:
Well, after working with my P2715Q for a couple of days on actual work my opinions have changed...

While I thought 30hz would be OK initially - turns out it gave me a headache. The mouse pointer moving jaggedly across the screen got annoying very quickly. I also thought I would be OK with 1920x1080 (HiDPI) - but I was missing the screen real estate offered by my old Apple Display (2560x1440).

For me these were two major issues, and I decided against trying to run 4K from the MacBook. Really a 5K display is what I need - i.e. running 2560x1440 at HiDPI - and that just isn't possible with the MacBook (and you could say its not really the target market of the machine).

For the next day I ran the display at a scaled resolution of 2560x1440 which I was almost happy with - but it wasn't as good as my initial impressions and I didn't actually find it as clear/sharp as my old Apple Display after all.

I figured if I couldn't run 4K properly then it would be silly to stick with a 4K display running a low quality scaled resolution, and that I'd rather get a decent quality 2K screen and have more screen real estate. So, thanks to Amazon's great returns policy, I'm now going to return the P2715Q.

I've replaced it with a U2715H which I've been using today and its absolutely fantastic - it actually is clearer/sharper than my old Apple Display was. It was also cheaper and has a much more modern design than the P2715Q had with a slim bezel. :)
Click to expand...
Great feedback, what kind of mac do you own? Integrated graphics? Or were you running it with the intel graphics? Thanks in advance
 
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