hkngo007 wrote:It's the first time i heard those 240hz monitors are native 180hz, where did you get this information. Do you work in the panel industry or something and in the know?
Well...
The truth is somewhere in between.
LCD pixels don't have a native refresh rate. Zis commandeered a 4K60 panel to be able to do 480Hz, an impressive 8:1 ratio above original specifications.
The limiting factor is the TCON, how much power you can put into the panel in such a short time period.
The electronics in the TCON (
Timing
CONtroller, the last circuit board thingy attached to the LCD panel via ribbon cable) may be rated for 150Hz, 180Hz, 200Hz, 240Hz, or whatever, but a monitor manufacturer sometimes replaces the TCON with a higher-Hz capable one.
The amount of power that can be injected into the LCD panel very quickly with the drivers on the edge of the LCD board, can often be the limiting factor for the LCD -- the briefer you refresh a pixel, the less reliably the LCD pixel behaves (ghosts more, transitions slower). So you may have fast pixel response at native Hz but very slow pixel response at overclocked Hz (more ghosting/smearing). Overdrive algorithms have to be amplified a little more during higher Hz or overclocking.
We don't always know which manufacturers replaces the TCON. But many do! NVIDIA often does for GSYNC (aka that "GSYNC module" is a custom-made TCON). Though that is becoming less necessary nowadays. So even if the panel originally had a 200Hz TCON, it's probably gone already, it's replaced by a native-240Hz GSYNC TCON. The LCD pixels themselves have no refresh rate built into them. Other times, there are modifications to the original TCON, or yes, even the original TCON is actually overclocked. (e.g. the 165Hz or 180Hz overclockables)
It's a continuum of degradation the faster you try to push LCD pixels, but I've seen 200Hz->240Hz panel modifications much higher quality than 60Hz LCD pixels. Often the endeavour of replacing a TCON isn't called (By manufacturers) an "overclocking" process. It gets nebulous/more complicated when you try to define what is overclocking, and what is not overclocking, in the era of panel-binning or chip-binning.
Even Intel does it, e.g. a 3Ghz-targetted chip may bin into 2.8Ghz, 3.0Ghz, 3.2Ghz, 3.4Ghz, and not even be called "overclocking" especially if the best-binned 3.4Ghz (metaphorically, it does it perfectly/stable as if it was not an overclock) does it more reliably than the worst-binned 2.8Ghz (metaphorically, unstably/problematically, as if it was overclocked at 2.8Ghz). So there's really a wide spectrum of overlap of how to define "overclocking" -- whether the manufacturers say it is or not -- and whether users say it is or not.
Panels are sometimes (not always) binned similarly, and sometimes panels are just manufactured as fast-GtG. That's why you have 1ms TN 60Hz panels....Many of them can do 144Hz with a custom replacement TCON without any overclock artifacts, but TCON modification is often more expensive than buying a new 144Hz monitor from scratch. Or to add new features like VRR -- Occasionally, TCON modification has happened like for the
ASUS VG248QE GSYNC Upgrade Kit (now discontinued) that was available in 2013. But it's not for the faint of heart.
So reading the specs on Alibaba/Aliexpress-style supplier websites, isn't always a reliable indicator of what workarounds a manufacturer is doing. They often include a basic TCON that is sometimes/not always used when these panels are installed in gaming monitors.
And even the same panels can have different TCONs (e.g. TN 1080p 1ms 60Hz and TN 1080p 1ms 144Hz panels are often exactly the same LCD glass but with different TCON circuit). And there might be a 60Hz, 144Hz, 200Hz, 240Hz versions of the TCON attached to the same 1ms-capable TN panel. (Assuming the panel has enough headroom to be driven by any of them)
There exists a continuum of degradation. LCD color quality and black levels does degrade
in general at higher refresh rates, so there's a continuum of degradations. The name of the game is to try to use panels that have almost unnoticeable degradation when increasing refresh rate up to a certain point, and to make good TCONs to make sure that does properly happen. But there's only so much electric current you can push into those grid microwires quickly enough in brief pulses at high-Hz. The briefer you try to refresh LCD pixels, the less accurate they become. You start hitting the edges of panel engineering limitations such as pixel transistor specifications and microwire resistance. The pixels of the active matrix switch less accurately at higher Hz, and other inconsistencies appear (such as differences in resistances of all the different microwires) creating artifacts such as poor contrast, ghosting artifacts, or splotchy blacks. And deciding what thresholds to call "overclocking" or not, can be nebulous.
LCD (Liquid Crystal Display) being analog molecules that block light, and these molecules have a momentum that fights against being faster pixel response. So there is just a slowly-degrading tradeoff effect the higher Hz you go. Molecules don't have the refresh rate. It's not like "You go above "###" Hz and the panel suddenly stops working" (that's the TCON or driver electronics that's suddenly failing, you can always upgrade those). There's always degradation at higher Hz. It may be a 1%->2%->3%->5%->10%->20%->50% degradation curve the more you step up Hz in steps. There's often also electronics circuits built into the panel glass edge (e.g. row-driving electronics that go between TCON and the pixels), which can provide another sudden-failure avenue. Sometimes some unexpected headroom occurs --
like the 60Hz laptop that overclocked to 180Hz. It varies from panel glass to panel glass. And the curves changes depending on the panel you attach the TCON too. Sometimes it's so tiny it's not noticeable (e.g. some panels might have a tiny 1% degradation for doubling Hz from 60Hz to 120Hz). Even binning is a big problem. Does one consider a 10% degradation as an overclock behavior, or a 25% degradation as an overclock behavior, etc. And things like "What does 10% degradation" mean? (contrast ratio loss? uniformity loss? How do you define a cutoff threshold for degradation, via a measuring device, etc). In many cases, the complexity of binning LCD panels simply is not done, and you just have a single panel that meets specs, then attach increasingly expensive TCON's (cheaper 60Hz TCON or more expensive 144Hz TCON) to the same panelglass, to save the costs of binning labour.
So it is useless to do the polarized Yes/No "Overclocked/Not" nitpicking, it's not that simple.
So, again...
The Truth is somewhere in between.
LCD pixels have no native "refresh rate" in them....