Dell P2715Q and P2415Q 4K IPS Displays

[ralkjdacp]

Check this out

http://embdev.net/topic/284710

It could be the issue you're experiencing, I have always had to use this fix to use HDMI monitors properly. Not sure about P2715Q 4k, but your observations sounds like issues I always seems to have with HDMI monitors.

Thanks for the tip; I was able to install the mod and confirm that it the EDID override is activated. Unfortunately, the quality of the text is still poor to my eye.

I did some reading up about HDMI cables. Turns out it's pretty confusing, as some sources used to claim that they are all the same, but that's not entirely true. Turns out there's a 'high speed' variant (with or without ethernet pass-thru, which doesn't matter), and I'm betting my cable is an older, standard version. I'm ordering a proper high speed HDMI cable now in the hopes that will produce a better picture.

UPDATE: I received a 'high-speed' HDMI cable and plugged in, and the quality looked the same. I did, however, notice that the SHARPNESS of the display was the primary culprit. Set all the way up to 100, the text looked poorly rendered to my eye; when I decreased sharpness to 50, it looks much, much better. I haven't plugged in the old HDMI cable to see if the cable makes any difference because I'll just use the high speed one.

 

[wakele]

What's the point of a 2560x1440 screen from a 4k monitor if it isn't HiDPi? It's not different than the Thunderbolt ACD. The point of me wanting 2560x1440 is for the HiDPi.

So basically, the only HiDPi mode available on the 27 or 24 is 1080p?

No, this is the only available mode if you have a discrete graphics board like I do. I've read that some graphics cards they can handle 1440p hidpi, and then they convert the image to 4k before sending the signal to the monitor, but my iris graphics 5100 is not able of that...and I think the rmbp 13'' has the same graphics card, so, for you, the best you can achieve is 1080p hiDpi by the moment, which I think is enough for the 24'' monitor. Only when I need many real estate to work, I go to 1440, not so sharp but more useful to work in. For any other thing, 1080Hidpi it is fantastic.

 

[WorldIRC]

Dell P2415Q with MacBook Pro Retina 15" mid 2014

The monitor works great with the mDP cable from Dell to the DP input on the monitor. I get 3840x2160 resolution at 60 hz.

Discrete or Integrated GPU?

 

[KenV54]

Discrete or Integrated GPU?

Both--but the Discrete graphics appears to be the one being used.

 

[WorldIRC]

Both--but the Discrete graphics appears to be the one being used.

I wonder if the integrated will work...

 

[larrysing1963]

I wonder if the integrated will work...

Yes. I have the late 2013 rMBP 15" with the Iris Pro Graphics ONLY (no discrete GPU) and I use the P2715Q at 60Hz and 3840x2160. See attached photo.

 

[KenV54]

Yes. I have the late 2013 rMBP 15" with the Iris Pro Graphics ONLY (no discrete GPU) and I use the P2715Q at 60Hz and 3840x2160. See attached photo.

Glad you were able to answer that question. Apple had told me the same thing when I was originally going to buy a rMBP with only integrated graphics. I ended up buying the one with both integrated and discrete a little cheaper and much faster (Amazon discount, for one thing, and Apple had to "upgrade" a machine to get the integrated only) than the one with no discrete card.

So, I tried the gfxCard https://gfx.io/ and switched to integrated only, and the external display wouldn't run. But if all you have is the integrated graphics, not both, then it will run without problems.

 

[larrysing1963]

Glad you were able to answer that question. Apple had told me the same thing when I was originally going to buy a rMBP with only integrated graphics. I ended up buying the one with both integrated and discrete a little cheaper and much faster (Amazon discount, for one thing, and Apple had to "upgrade" a machine to get the integrated only) than the one with no discrete card. So, I tried the gfxCard https://gfx.io/ and switched to integrated only, and the external display wouldn't run. But if all you have is the integrated graphics, not both, then it will run without problems.

Further confirmation of my system attached.

 

[WorldIRC]

Glad you were able to answer that question. Apple had told me the same thing when I was originally going to buy a rMBP with only integrated graphics. I ended up buying the one with both integrated and discrete a little cheaper and much faster (Amazon discount, for one thing, and Apple had to "upgrade" a machine to get the integrated only) than the one with no discrete card.

So, I tried the gfxCard https://gfx.io/ and switched to integrated only, and the external display wouldn't run. But if all you have is the integrated graphics, not both, then it will run without problems.

I guess on a machine that has both GPUs, the mDP ports are wired only to work with the Discrete card?

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Yes. I have the late 2013 rMBP 15" with the Iris Pro Graphics ONLY (no discrete GPU) and I use the P2715Q at 60Hz and 3840x2160. See attached photo.

Glad to hear -- I guess the second port won't work as well, right? Would have to use HDMI @ 30hz?

 

[larrysing1963]

I guess on a machine that has both GPUs, the mDP ports are wired only to work with the Discrete card?

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Glad to hear -- I guess the second port won't work as well, right? Would have to use HDMI @ 30hz?

I don't completely understand the question, but as you can see on my image, I'm getting 60Hz to two external monitors, each using the mDP/TB ports on the MacBook.

I don't know for CERTAIN that a second monitor running at MORE than 3440x1440 would run at 60Hz, because I don't have two 4K monitors for testing.

But for sure, you can run two at minimum 3440x1440 each, both at 60Hz at the same time.

 

[WorldIRC]

I don't completely understand the question, but as you can see on my image, I'm getting 60Hz to two external monitors, each using the mDP/TB ports on the MacBook.

I don't know for CERTAIN that a second monitor running at MORE than 3440x1440 would run at 60Hz, because I don't have two 4K monitors for testing.

But for sure, you can run two at minimum 3440x1440 each, both at 60Hz at the same time.

Ya that's where I was getting at. Was wanting to run two 4K monitors at 1080P or 1440P HiDPI.

 

[larrysing1963]

Ya that's where I was getting at. Was wanting to run two 4K monitors at 1080P or 1440P HiDPI.

Oh you can for sure do that. Two by 4K is still questionable, but we know that 4K & 1440p are possible both at 60Hz by using my own example.

 

[WorldIRC]

Oh you can for sure do that. Two by 4K is still questionable, but we know that 4K & 1440p are possible both at 60Hz by using my own example.

Ya but if I run at 1080P HiDPI, isn't it still considered to be running at 4K, just scaled, as opposed to having a monitor that actually runs at 1080P.

 

[larrysing1963]

Ya but if I run at 1080P HiDPI, isn't it still considered to be running at 4K, just scaled, as opposed to having a monitor that actually runs at 1080P.

Both of my monitors are HiDPI using SwitchResX. See picture.

 

[WorldIRC]

Both of my monitors are HiDPI using SwitchResX. See picture.

Nice - so I guess the only question left is what happens if the second monitor is also a 4K monitor.

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For those of you using the P2415Q -- how sharp does 1080P HiDPI appear? Is it significantly better than a regular 1080P monitor? No loss of sharpness as a result of scaling?

 

[larrysing1963]

Nice - so I guess the only question left is what happens if the second monitor is also a 4K monitor.
----------
For those of you using the P2415Q -- how sharp does 1080P HiDPI appear? Is it significantly better than a regular 1080P monitor? No loss of sharpness as a result of scaling?

Yes, still an unknown. Some reports have said that the second monitor goes blank when it attempts to go 60Hz. One can go 60Hz, but the other only 30Hz. That might be with older OSX drivers though. I'd love to see that attempted on a 10.10.2 or a 10.10.3 computer.

 

[stempsons]

Yes, still an unknown. Some reports have said that the second monitor goes blank when it attempts to go 60Hz. One can go 60Hz, but the other only 30Hz. That might be with older OSX drivers though. I'd love to see that attempted on a 10.10.2 or a 10.10.3 computer.

i

 

[zeiter]

I have two questions:

1) if your monitor is detected as a television, then you don't have the full RGB range. From the pictures I saw, most of your displays are detected as televisions by your computer....as a photographer, I need full RGB range.

2) If I scale the 24 inch version to show 1440p in HiDpi, will it be usable?

thank you

 

[larrysing1963]

I have two questions:1) if your monitor is detected as a television, then you don't have the full RGB range. From the pictures I saw, most of your displays are detected as televisions by your computer....as a photographer, I need full RGB range. 2) If I scale the 24 inch version to show 1440p in HiDpi, will it be usable? thank you

As to your question 1, I moved the monitors to full RGB space. See attached picture for the updated System Report showing them NOT as televisions.

Question#2, I can't answer, as I don't own the 24" version, sorry.

 

[KenV54]

I'm going to repost in short form two of my original questions,

1) Does any one know if the DP Out on a Dell P2415Q monitor will support HDMI to daisy chain to a Dell ST2310 monitor with only HDMI, DVD-D and RGB inputs? I'm trying to figure out if the problem is with my cheap DP to HDMI adapter, or if it just can't be done. It isn't the HDMI cable, because I've tried several of those.

2) Using mDP to DP from the rMBP mid 2014 to the P2415Q, and HDMI from the rMBP to the HDMI input on the Dell ST2310, is there any way to get an extended screen /without/ the Desktop icons being on the right side of the secondary (ST2310) monitor; that is, to have a completely empty secondary monitor screen except for the Desktop background?

 

[aviduser2]

Deicided to pull the trigger on the P2415q.

I'm coming from a u2713hm, and i was looking for a smaller monitor (e.g. 23-25) since i found the 27" to big, BUT i really enjoyed 1440p resolution.

So i narrowed down my choices to
-U2515
-P2415q

Usually the p2415q is $200 more expensive in my country, but i managed to get my hands on a cheaper copy, so basically the price for the both was equal and i felt i couldnt pass on that opportunity.

In 1080p HiDPI it's gorgeous. Even in 1440p it looks very nice (although not as sharp as native).
Something that bothers me is that when i run in 1440p the computer get very warm when running applications like youtube/twitch which i find annoying.

So any thoughts on the p2415q vs U2515H? Maybe it would just be stupid to consider it, but i figure i throw it out here.

I also wonder if it it's possible to run screen @1440p WITHOUT hi-DPI scaling (If possible, do i need Switchres?)

Because when i run 1440p on this screen, and i go into the screens menu, it says 3840*2160 @60hz. BUT i assume it's downscaled from 4k res to 1440p? (e.g. will be heavier to drive then regular 1440p screen)

 

[Sheza]

Deicided to pull the trigger on the P2415q.

I'm coming from a u2713hm, and i was looking for a smaller monitor (e.g. 23-25) since i found the 27" to big, BUT i really enjoyed 1440p resolution.

So i narrowed down my choices to
-U2515
-P2415q

Usually the p2415q is $200 more expensive in my country, but i managed to get my hands on a cheaper copy, so basically the price for the both was equal and i felt i couldnt pass on that opportunity.

In 1080p HiDPI it's gorgeous. Even in 1440p it looks very nice (although not as sharp as native).
Something that bothers me is that when i run in 1440p the computer get very warm when running applications like youtube/twitch which i find annoying.

So any thoughts on the p2415q vs U2515H? Maybe it would just be stupid to consider it, but i figure i throw it out here.

I also wonder if it it's possible to run screen @1440p WITHOUT hi-DPI scaling (If possible, do i need Switchres?)

Because when i run 1440p on this screen, and i go into the screens menu, it says 3840*2160 @60hz. BUT i assume it's downscaled from 4k res to 1440p? (e.g. will be heavier to drive then regular 1440p screen)

Well as someone with a 13" rMBP I'm not able to run the p2415q at 60 Hz so I'm going to go for the U2515H

 

[k-hawinkler]

I received my P2715Q and the display itself seems to be working fine on my nMP.

DELL P2715Q:
Resolution: 3840 x 2160 @ 60 Hz
Pixel Depth: 32-Bit Color (ARGB8888)

I hooked it up with the three cables that came in the box, namely:

• Power cable (varies by country)
• USB 3.0 upstream cable (enables the USB ports on the monitor) and
• DP cable (mDP to DP)

Whereas the display itself works great the USB downstream ports (4) don't seem to work at all, neither with a keyboard, mouse nor an Apple USB SuperDrive.

What am I missing?
Do I have a defective unit that needs to be send back?
Or did I overlook something?
TIA for your feedback.

So, I explored the issues I encountered with the USB in the P2715Q display and found the following:

• An Apple Keyboard and a Microsoft Intelli Mouse work correctly when attached to the USB in the P2715Q display.
• My Apple USB SuperDrive doesn't work at all. I can't even stick in a CD.
• However, my Apple USB SuperDrive works fine when directly attached to the 6-core nMP.
• An Apricorn SATA Wire USB 2.0 Upgrade Kit with 512 GB Crucial M4 SSD crashes the nMP when I try to copy files to it.
• This also crashes the nMP when the USB is directly attached to the nMP.
• However the Apricorn works correctly when attached to a 2009 17" MacBook Pro.

Question: What experience do you have with using the P2715Q display USB?

 

[martinm0]

4k rez setting MST = Secondary

Had an interesting discovery today messing around with the MST setting on the P2715Q. Neither of my computers officially support 4k resolutions (late 2012 iMac 3.4, 680MX and Dell E6430 laptop work issued).

The Dell laptop sits in a dock with DP, DVI and VGA out. I was hoping to use the DP out from the Dell monitor to my older Dell with DP in. Nothing happened when I set MST to Primary, so I flipped it over to Secondary setting and got an image on the Dell 27" monitor. To my surprise, it was a full 3840x2160 (monitor claimed 60Hz, but it was pretty choppy). Still, I didn't think the Intel GPU would do 4k (without MST I can only select 2560x1440 max).

Hooked up the iMac and set MST to Secondary and BAM, 4k! Again, monitor claims 60Hz, but System Information shows 30Hz.

Am I missing something about MST here? Is this a magic button for us with older macs that want 4k (albeit crippled)? It just doesn't make sense to me at all.

EDIT: the Dell monitor is reporting 30Hz, not 60Hz. I was stupidly looking at the max settings, not the actual. Additionally, I hooked up my wife's Macbook Air w/ HD3000. It would not do 4k with MST set to Secondary, but it would to a HiDPi 1080p (no option for 2560x1440). When I turned off MST entirely, I could do 2560x1440.

This is all really strange, yet very cool. The HiDPI options looks really, really good. The scaling on the iMac also looks great. Though, it seems the DP port provides a better image than the mDP port. Both support the MST setting (or both offer 4k when I set MST to Secondary), but there is some ghosting around text on the mDP. I don't recall the DP port having that and instead looks damn crisp.

 

[wakele]

I also wonder if it it's possible to run screen @1440p WITHOUT hi-DPI scaling (If possible, do i need Switchres?)

Because when i run 1440p on this screen, and i go into the screens menu, it says 3840*2160 @60hz. BUT i assume it's downscaled from 4k res to 1440p? (e.g. will be heavier to drive then regular 1440p screen)

Yes you can, I get this resolution with switchresx, but I think you don't need it to work with 1440p "lowDpi". Are you sure you are not checking the maximum resolution of the screen (on the right side of the osd) instead of the current resolution (left side of the osd).