DP++ 1.1 port with 2560x1440 display

[DiggityDug]

Super frustrating pre-purchase paralysis for something I thought would be fun & easy... Started looking for an upgraded monitor for my work laptop.  It's a solid laptop, but only has Intel's HD 4000 chip which only supports DisplayPort 1.1. 

 

All the documentation says a DP++ 1.1 port should be able to easily support 2560x1440 at 60Hz, but then I started reading the FLOOD of bad reviews for 2K monitors, especially with people hooking them up to laptops... BLANK SCREEN... 1080p ONLY, WONT DO 1440p... and on and on they go.  Then I got super-deep into DP++ dual-link mode specs, active vs passive adapters, etc, etc.  Total analysis paralysis.

 

This is insane!   All I want to know is does a 1.1 DP++ port support 2560x1440, and if so, what cable(s) do I need to go from a mini DP++ to a 1440p monitor that as DVI, DP, and HDMI inputs? The situation is further confused by the monitor manufacturers claiming that the ports on the back of the monitor support different resolutions.  This is so ridiculous! Total analysis paralysis on my part, but it's a big decision since returning a 27" monitor is a huge pain.

 

Thanks All,

[N.tony]

https://en.wikipedia.org/wiki/DisplayPort#Resolution_and_refresh_frequency_limits_for_DisplayPort

 

I think this should help

[Badger906]

1: welcome to the forum

2: 2k is 1080p not 1440p, K refers to the number of horizontal pixels, 1920x1080 being 2k and 2560x1440 being 2.6k.

3: displayport 1.1 supports 2560x1440 upto 75hz. using any standard display port 1.1 or greater cable.

[Glenwing]

1 hour ago, DiggityDug said:

Super frustrating pre-purchase paralysis for something I thought would be fun & easy... Started looking for an upgraded monitor for my work laptop.  It's a solid laptop, but only has Intel's HD 4000 chip which only supports DisplayPort 1.1. 

 

All the documentation says a DP++ 1.1 port should be able to easily support 2560x1440 at 60Hz, but then I started reading the FLOOD of bad reviews for 2K monitors, especially with people hooking them up to laptops... BLANK SCREEN... 1080p ONLY, WONT DO 1440p... and on and on they go.  Then I got super-deep into DP++ dual-link mode specs, active vs passive adapters, etc, etc.  Total analysis paralysis.

 

This is insane!   All I want to know is does a 1.1 DP++ port support 2560x1440, and if so, what cable(s) do I need to go from a mini DP++ to a 1440p monitor that as DVI, DP, and HDMI inputs? The situation is further confused by the monitor manufacturers claiming that the ports on the back of the monitor support different resolutions.  This is so ridiculous! Total analysis paralysis on my part, but it's a big decision since returning a 27" monitor is a huge pain.

 

Thanks All,

https://linustechtips.com/main/topic/729232-guide-to-display-cables-adapters-v2/?section=maximum_limits

17 minutes ago, Badger906 said:

1: welcome to the forum

2: 2k is 1080p not 1440p, K refers to the number of horizontal pixels, 1920x1080 being 2k and 2560x1440 being 2.6k.

3: displayport 1.1 supports 2560x1440 upto 75hz. using any standard display port 1.1 or greater cable.

The convention generally is to round to the nearest 0.5K, no one rounds to the nearest 0.1

[Badger906]

2 minutes ago, Glenwing said:

https://linustechtips.com/main/topic/729232-guide-to-display-cables-adapters-v2/?section=maximum_limits

The convention generally is to round to the nearest 0.5K, no one rounds to the nearest 0.1

so youd list 1366x768,1440x900, 1680x1050 as 1.5k and 1280x800, 1280x720 ect as 1k?!?! i know K is really bad means of categorising a specific resolution, but if it becomes more standard the 0.1 will make all the difference

[Glenwing]

4 hours ago, Badger906 said:

so youd list 1366x768,1440x900, 1680x1050 as 1.5k and 1280x800, 1280x720 ect as 1k?!?! i know K is really bad means of categorising a specific resolution, but if it becomes more standard the 0.1 will make all the difference

No, I wouldn't use K for lower resolutions at all, and in general people don't. It's not supposed to be a universal naming convention, it's just a vague shorthand.

 

This shorthand is a convention that is already established and has been used for many years, I'm just saying how it is used. If you think it doesn't make sense that's ok, but we're not taking a vote on what the convention should be. Nearest 0.5 is what's used, and that's all there is to it, whether you think it makes sense or not.

[DiggityDug]

Thanks, you confirmed that at least I'm looking at the right documentation.  However here is where I get stuck.  For both of the monitors that I'm researched, their documentation says something like the following (This is for a pretty well-rated Acer model with DVI, DP, and HDMI inputs).  Don't you read the following as having to use an active dual-link DVI-D connection to get the full 1440p resolution? I suppose Acer could be wrong, but this seems like their wheel-house:

The K272HUL monitor supports the following maximum resolution.

• DUAL LINK DVI - 2560x1440 @ 60Hz
• DisplayPort (DP) - 1920 x 1080p @ 50Hz
• HDMI - 1920 x 1080i @ 60Hz

Note: These resolutions are only available if the video card is capable of supporting them.

https://us.answers.acer.com/app/answers/detail/a_id/34302/~/acer-k272hul-monitor-inputs-and-maximum-resolutions

[Glenwing]

13 minutes ago, DiggityDug said:

Thanks, you confirmed that at least I'm looking at the right documentation.  However here is where I get stuck.  For both of the monitors that I'm researched, their documentation says something like the following (This is for a pretty well-rated Acer model with DVI, DP, and HDMI inputs).  Don't you read the following as having to use an active dual-link DVI-D connection to get the full 1440p resolution? I suppose Acer could be wrong, but this seems like their wheel-house:

The K272HUL monitor supports the following maximum resolution.

• DUAL LINK DVI - 2560x1440 @ 60Hz
• DisplayPort (DP) - 1920 x 1080p @ 50Hz
• HDMI - 1920 x 1080i @ 60Hz

Note: These resolutions are only available if the video card is capable of supporting them.

https://us.answers.acer.com/app/answers/detail/a_id/34302/~/acer-k272hul-monitor-inputs-and-maximum-resolutions

DisplayPort 1.1 allows enough bandwidth for up to 2560×1440 at ≈75 Hz but it's not required that monitors be capable of full bandwidth, so yes it's possible that the monitor may have its own limitations that are lower than the maximum that the DP 1.1 standard allows, and it wouldn't be the first time I've seen it before. It's unusual to see it with DisplayPort though, usually I only see it with HDMI.

[DiggityDug]

Ok, so hopefully this helps someone else who's looking for a high-res monitor on an old(er) laptop   I ended up heading down to the local Fry's with my laptop and hashing it out with some good old-fashion testing (and nerding out with the guy that works at Fry's).

 

Really Cheap 1440p Displays that only support dual-link DVI are not a good option.  This is the least-expensive interface, but is not natively compatible with DP++ 1.1 due to there not being enough physical pins in the displayport interface. Any passive converter will only be single-link and the monitor will either not work, or wil ldown-scale to 1080p.  You can buy and "active" DP++ adapter that double the signaling rate coming out of the DP++ and then splits it out into dual-link DVI, they are are around $100, so just buy a better 1440p monitor instead (More on this below)

 

Mid-grade 1440p might work, depending on the manufacture.  I confirmed this is mostly due to a cheaper implementation of the DisplayPort interface that will either do DP 1.2 signaling, or force the connection down to single-link DVI leaving you with 1080p.  But on the other hand, I tested some mid-grade monitors like the Asus PB277Q and PB278Q that had an select-able option for DP 1.2 or DP 1.1.

 

Upper-end of the mid-grade ($350+) and higher-end models all seemed to work without any fuss. Some smarter than others, like an HP that automatically figured everything out (no settings changes required) and the higher-end gaming version of the Asus monitor also had the selectable option for DP 1.2 or 1.1.

 

Hope that helps, turns out there's still some value in the good old brick-n-morter computer stores