So you know when you purchase a car and like you know the motor of three different models is the same, aside from software engine management making a series 160, 180 or 200 model? See it's much cheaper to produce one product as opposed to three different ones. The same with CPUs, which are binned but really inside it's all the same?

I just popped over TPU who has a really funny lead towards Germany based PRAD, experts in display technology. And they have a story that fits the thesis I described above. Manufacturers all try to produce as little models of a product for economic reasons, and so that seems to be the case with Quad HD and Ultra HD panels lately. There's a tipping point that makes UHD panels cheaper to fab when the volume is high enough. Sometimes it's cheaper to create bigger batches. So in their testing PRAD discovered that certain Wide Quad HD monitors (2560x1440) actually make use of an Ultra HD panel, which scales down and interpolates towards 2560x1440.

So you could already be sitting in front of a 4K monitor, without knowing it :-) However, that doesn't mean it's good news. The cost of producing a 27-inch 4K UHD panel (3840 × 2160 pixels) is now at least as expensive or even cheaper than producing a QHD panel (2560 × 1440 pixels). Depending on the volume order, a higher-resolution panel is simply installed in the event of supply shortages, as actually specified in the datasheet. However, the panel is then (and pardon the wording) castrated by firmware and displays a QHD resolution. PRAD specifically mentions it is not clear how many models are currently being released into the market this way. Also, They were assured that flashing the firmware would not lead to the revamping a display into a 4K UHD monitor. 

So how would you know what panel you have?  First, the specifications datasheet or manual of the manufacturer really should mention it as a manufacturer is obligated to communicate this in a transparent way.

Physically checking it out - just look - a test pattern with a fine pixel structure can show whether everything is crisp and sharp or whether it is interpolated. Most users will not notice this, but the monitor 2560x1440 is not operating in its native resolution (UHD), thus pixels at a QHD resolution are not displayed 1:1 pixel-accurate. This inevitably leads towards a bit loss in sharpness. You could perceive a minimal loss of sharpness perhaps in text reading as usually an anti-aliasing is used in the font display. Regardless, since a firmware won't get you to UHD, researching seems useless anyway. But it's an interesting observation I'd say.

Your Quad HD 2560x1440 Monitor Could Actually have an Ultra HD Resolution Panel