U2711, cannot reach 2560x1440 resolution on new laptops, DVI-dual link

It may be prudent to have a read of this too:
https://www.tomshardware.com/features/displayport-vs-hdmi-better-for-gaming

Hmm . . . Took a quick look at your laptop specs and noticed "DisplayPort over USB-C".

A quick google of that took me to:

https://www.dell.com/support/article/en-au/sln296827/displayport-over-usb-type-c?lang=en

and

https://www.amazon.com.au/DisplayPort-CableCreation-Thunderbolt-Compatible-Chromebook/dp/B072ZT9RQZ

I have no personal experience of this but it looks like you might well have that sort of thing as another option.  As I said above, USB-C wasn't around 10 years ago when I had the issue.

Please post an update of what you manage to achieve.  You probably have an HDMI cable lying around somewhere, so maybe try that first anyway.  Enjoy!

Hi Albert @Deinamite,

I'm not sure from where you got my name but suspect it was from my earlier posts on the U2711.  If so, you've probably already seen the answer, although it's probably not what you want to hear.

We're going back a decade, so my memory may not be 100% accurate but my suspicion is that your HDMI to DVI-D cable may not be doing what you think.  In other words, it's operating as single link, not dual and thus won't support the 2560 x 1440 resolution at 60 Hz & 32 bit colour.

Similarly, I doubt you'll find a HDMI to DP or USB-C to DP that will work either (although USB-C wasn't even around back then, so who knows).

Regardless, you may well need:

1) DP connection but you probably lack that output (and as mentioned above, I doubt you'll get a working conversion, at least not at a reasonable price).

2) Dual link DVI connection but . . . see 1) above.

3) HDMI with a high speed cable plus a custom resolution.  This may well be your only realistic option.

You'll find my thread on that at:
https://www.dell.com/community/Monitors/U2711-HDMI-2560x1440/m-p/3438251#M76134

That also contains a link to very lengthy discussions predominantly about obtaining a full resolution HDMI connection (but also mentions active vs passive HDMI to DP connectors and HDMI to DVI connectors that appear dual but are effectively single) at:
http://forums.whirlpool.net.au/forum-replies.cfm?t=1479962

Anyway, the net result is that I very much suspect that your only option will be an HDMI connection and whilst that's not officially supported (i.e. official HDMI max is 1920 x 1080) it can be achieved via a custom resolution (or editing the EDID file).

An example is at the end of that Dell thread, there are many others on that Whirlpool thread who confirm this too, as well as myself who used HDMI to U2711 at 2560 x 1440 at 60 (59?) Hz for several years, before moving to DP with a new PC.

Good luck!

@Deinamite  HDMI to DVI-D cables do not work for dual link connections.  Yes, many HDMI outputs support 2560x1440 or better, and yes dual link DVI supports 2560x1440, but HDMI outputs cannot send a native dual link DVI signal (nor can a dual link DVI source signal be sent into an HDMI input, although I realize that's not the direction you're trying to go here.)  The bottom line is that simple passive HDMI to DVI adapters and cables cannot be used to carry a dual link DVI signal, even though all of the pins are there, and I'm not even aware of any "active" HDMI to dual link DVI converters.  There are DisplayPort to dual link DVI and USB-C to dual link DVI adapters, which are expensive, but I haven't seen anything that involves HDMI.

However, since your display has a DisplayPort input, if your system has a USB-C port that supports DisplayPort Alt Mode video output -- which is an optional capability of USB-C ports and not always implemented -- then a USB-C to DisplayPort cable/dongle is your best bet.  They're not very expensive at all.  But if you don't have a video-capable USB-C port or a native DisplayPort output, then as far as I know, you won't be able to send 2560x1440 to that display from that system.  HDMI to DisplayPort cables/adapters will not work for sending an HDMI source to a DisplayPort display.  They only work in the opposite direction (and they're limited to 1920x1200 anyway unless you get an "active" adapter that supports something better).

@Deinamite  Actually I might have good news for you.  Even if your systems don't have video-capable USB-C ports, I found this active converter that is explicitly designed to convert an HDMI source signal to a DisplayPort output, so as long as your system supports at least 2560x1440 via HDMI, you can use this converter to send that to your display's DisplayPort input.  Note that this conversion direction is the opposite of the way the vast majority of DisplayPort to HDMI adapters work, so if you decide not to buy the exact product I linked (although I definitely recommend Cable Matters since they have a solid reputation for quality products), then be very careful looking at alternatives, because most DisplayPort to HDMI adapters -- including most active ones -- are designed to switch a DisplayPort source signal to HDMI.  (The USB connection required by this converter is for power.)

Exactly @jphughan, IIRC, HDMI is a Single Link and Dual Link DVI is obviously Dual Link and thus I understand that you need active (i.e. powered) electronics to convert from one to the other.  As such, passive connectors don't work (even when they look like they will) which is probably what @Deinamite is trying to use.

That active connector you found looks interesting @jphughan.  As you said, most go the other way.  The only remotely similar thing that I could find a decade ago cost well over $100 and I wasn't even confident it was fit for purpose, so I never tried.  However, at USD $36 that might be worth a try, especially as @Deinamite should already have the required additional DP cable (as it came with the U2711).

That said, the DP over USB-C looks interesting too and may provide a simpler & cheaper solution.  I wonder if anyone has experience of actually using it.

Moreover, the straight HDMI to HDMI connection CAN work (although sometimes there are difficulties / 'issues').  It's probably worth a try as @Deinamite is bound to have an HDMI cable and thus it's a no cost potential solution.

NB How did you get your later message to listed before your earlier one @jphughan

Hi @jphughan 

Thanks! See my response to @jphughan .

I have tried everything I can, and I will take a look at the active hdmi to DP adapter.

However, even if it would work, it would not be convenient as I would have to switch cables every time I switch between Surface laptop and Acer laptop,

Hi @Guerdon,

Thanks for your clear answer (great to see people helping each other).

Unfortunately I am very close to the conclusion that it will be impossible to get the desired resolution from the hdmi or dvi-d inputs, must be something hard-coded wrong in the Dell U2711.This is what I tried:

1. Connected my new Acer laptop with a high-speed hdmi cable to my LG 65" OLED television. Immediately and automatically it displayed at 4k. Conclusion, no problem with the hdmi output of the laptop, and no problem with the hdmi cable

2. Connected the new laptop with the U2711 via HDMI - DVI-D cable. max resolution still very low. Created custom resolution in NVIDIA control panel, but doesn't work, picture very bad

3. Connected the new laptop with the same hdmi cable as used under 1., but same problem as in 2. I cannot get the resolution up, despite all the force (created 2560*1440 at low refresh rates, high rates, I tried everything, nothing works)

4. My Surface laptop 2 with mini DP output does give a very nice 2560*1440 picture via mDP - DP cable. 

This is all very strange, I think the model simply does not allow higher resolutions on other ports than the Display Port. The only thing I can still try, is buy one of those hdmi to DP active adapters, but that would still give problems, as I then need to switch cables every time I switch between Surface laptop and Acer, mmmhhh.

I guess I need to buy a new monitor ........

@Deinamite  If you get either a USB-C to DP dongle (not cable) or the active HDMI to DP dongle I linked earlier in order to cover your Acer system, and then a Mini-DP to DP dongle (not cable as you have now) in order to cover your Surface, you'll be able to use a regular DP cable with each system's respective dongle, in which case you'll just have to move that DP cable back and forth between dongles rather than having to actually switch cables.

@Guerdon The adapters you're referring to were likely Mini-DP to Dual Link DVI and USB-C to dual link DVI adapters.  Both of them were introduced primarily when MacBooks switched to Mini-DP/TB2 and then USB-C/TB3.  They were indeed over $100 each.  I guess it's a combination of the fact that dual link DVI is long dead and actually wasn't especially common even when it existed, since back then the only displays that needed it still cost well more than most people would spend on a display.  And by the time the cost of such displays had come down, DisplayPort had arrived.  Those factors of course make for a very limited market for such adapters.

I've used USB-C to DisplayPort often and it works brilliantly -- but it requires that the USB-C port support DisplayPort Alt Mode, and I couldn't find confirmation that the Acer Aspire 5 does, hence my active HDMI to DP adapter recommendation.  But as you found, DisplayPort Alt Mode is a standard, and in fact it's used by USB-C docks and even by TB3 docks, albeit encapsulated in a Thunderbolt signal in the latter case.  The adapters are inexpensive because there's no actual conversion going on since the USB-C port actually maps its pins to operate as a native DisplayPort output.  There are also USB-C to HDMI adapters/cables, which incorporate active converter chips to switch that DP signal to HDMI.  That plus the fact that HDMI requires manufacturers to pay a royalty on every HDMI port/connector they use while DP is royalty-free means that USB-C to HDMI cables/adapters tend to be a bit more expensive, but they're still quite reasonable, likely because the market for them is huge.  But given the choice I always go for USB-C to DP since not needing that active converter chip means I have one less thing to pay for and possibly cause problems.

The U2711's HDMI input is limited to 1080p, likely because it predates the existence of a newer HDMI standard that would have supported 2560x1440.  A similar thing happened with early 4K 60 Hz displays because they were created before HDMI 2.0 existed, so they're limited to QHD 60 Hz or 4K 30 Hz when fed via their HDMI inputs.  Otherwise yes that would have been the dead simple solution.

As for replies, this forum (currently) has a bizarre way of ordering posts.  If you click Reply to a particular post, it shows up directly under the reply you selected, or underneath any other posts written as direct replies to that one.  And apparently if the same person posts multiple replies to the same post, they're sorted newest to oldest.  I hate this entire system and am trying to get Dell moderators to switch the forum back to a basic "oldest to newest" ordering and restore the ability to quote the post you wish to reply to, which is how basically every sensible forum platform is designed.  The current design reeks of something that sounded like a good idea to someone who doesn't use forums very often, but the result is that it's impossible to quickly find the newest posts in a thread, and if recent posts were written as replies to completely separate posts on a larger thread, the newest posts might be separated by a few pages.  For people who actively try to help others on this forum, having to waste time finding where the new posts are hiding is irritating.

Perfect! That is indeed much better, I will try that, is much more workable than switching DP connector at the back of the monitor, will give it a try, order the dongles first now, thx!

@Guerdon  Interesting product, I guess.  But my original point was that I have never seen an active converter that can go from HDMI to dual link DVI, which is what the OP has been trying to do, or vice versa.  I've seen products that can convert from DisplayPort (as either DP, mDP, or USB-C) to dual link DVI, but never HDMI to dual link DVI.  And that product you linked doesn't seem to do that either, even setting aside its cost.

Yes, I know that active converters that go from HDMI to DisplayPort exist, but I typically don't mention them unless there's a clear use case for them (as is the case here), partly because there are often simpler and less expensive ways to connect whatever laptop and display the user has, and also because HDMI to DP converters are relatively rare and seem to be more finicky than the adapters that go in the opposite and much more common direction.  HDMI to DP adapters are also a bit of a pitfall because as I said, even if you just focus on ACTIVE adapters, adapters that go from DP to HDMI are much more common because those were created to be used with a) DisplayPort outputs that didn't natively support Dual Mode DisplayPort, b) use cases where Dual Mode DisplayPort wasn't allowed, such as AMD EyeFinity, and c) running higher resolutions than Dual Mode DisplayPort would natively send as HDMI.  So if you tell a user, "Hey, an active HDMI to DP adapter exists", there's a decent chance they'll accidentally buy an active adapter that goes the opposite direction.

The documentation of the U2711 only seems to indicate support for 1080p on HDMI.  But if you're speaking from experience saying that it supports native resolution over HDMI, then obviously real world experience trumps documentation every day.  In that case I agree that would be the much simpler solution, but then I'm left wondering why @Deinamite  isn't already doing that.  Was that actually never tested?

Definitely @Deinamite.

If you're prepared to buy those dongles that @jphughan mentioned and simply connect DP to to DP using the U2711 supplied DP cable (as mentioned yesterday) then that'll probably be your best solution because whilst HDMI to HDMI can work, it also can have 'issues'.