What would it take to make a 120hz *input* TV

[snuuggles]

As far as I know, there are no TVs on the market today that will actually accept and display 120hz signal from a computer.

Given that the new TVs have hdmi 1.4, and the old TVs *could have had* DVI-D ports, and that many of them already have a 120hz panel, what exactly was/is stopping the manufacturers from just providing the ability to use 120h as a real refresh.

It's been frusterating getting a good large-format screen that has truely good motion resolution. I've been trying out a 42" plasma, but 1. It's a little large for me, I'd prefer 32/37. 2. it buzzes and 3. it's not 120hz.

I can see why large-format "monitors" are not being made at 120hz, the larger monitors would be difficult to market with 1080p, and nothing but displayport will allow for higher resolutions @120hz.

But it's just weird to me that *not one TV manufacturer* has slapped a DVI-D port on thier 120hz tv and called it a "gamerz fury edition". Or something like that...

 

[Sentry2]

Are you sure they actually use 120Hz panels...? I thought all consumer grade TVs were using frame-interpolation to achieve the effect.... on the other hand though it looks like they have to use 120Hz panels to actually make use of frame-interpolation in the first place.

 

[LiuKangBakinPie]

As far as I know, there are no TVs on the market today that will actually accept and display 120hz signal from a computer.

Given that the new TVs have hdmi 1.4, and the old TVs *could have had* DVI-D ports, and that many of them already have a 120hz panel, what exactly was/is stopping the manufacturers from just providing the ability to use 120h as a real refresh.

It's been frusterating getting a good large-format screen that has truely good motion resolution. I've been trying out a 42" plasma, but 1. It's a little large for me, I'd prefer 32/37. 2. it buzzes and 3. it's not 120hz.

I can see why large-format "monitors" are not being made at 120hz, the larger monitors would be difficult to market with 1080p, and nothing but displayport will allow for higher resolutions @120hz.

But it's just weird to me that *not one TV manufacturer* has slapped a DVI-D port on thier 120hz tv and called it a "gamerz fury edition". Or something like that...

LCDs don't have a refresh rate. They're not CRTs. So 60mhz and 120mhz will look the same if you watch tv. To work out a LCDs real emulated refresh rate
1000/response time

 

[snuuggles]

TVs do not have 120Hz panels.

Hmmm, so I'm not really sure what you mean. I know that so-called "120hz" TVs don't accept a 120hz input, but they *do* refresh 120 times a second.

Logically, there's a certain part of the TV that switches the 60hz input to 120hz. Now, what it actually *sends* may not be more than a duplicate image every other frame, but the pixels themselves don't know that. All they do is update 120 times a second with whatever is sent to them.

I'm assuming there's a logic board in there that makes the swap-over, and that since it's *already* sending 120 signals a second to the ~2 million pixels (which I'm calling the panel, but I'm not sure that's correct), why not allow it to send 120 unique signals rather than 60 unique signales joined by 60 duplicates (geez, in some cases I'm guessing it's doing *more* work than that since it not only is converting 60 to 120, but doing interpolation so the frames aren't just duplicates but on-the-fly generated "in between" frames. That sounds harder to do than just taking 120 unique frames and passing them along untouched...

Again, aside from a DVI-D port and a seemingly minor change to the logic board, I'm *really* curious what else would need to be changed!?

 

[LiuKangBakinPie]

Hmmm, so I'm not really sure what you mean. I know that so-called "120hz" TVs don't accept a 120hz input, but they *do* refresh 120 times a second.

Logically, there's a certain part of the TV that switches the 60hz input to 120hz. Now, what it actually *sends* may not be more than a duplicate image every other frame, but the pixels themselves don't know that. All they do is update 120 times a second with whatever is sent to them.

I'm assuming there's a logic board in there that makes the swap-over, and that since it's *already* sending 120 signals a second to the ~2 million pixels (which I'm calling the panel, but I'm not sure that's correct), why not allow it to send 120 unique signals rather than 60 unique signales joined by 60 duplicates (geez, in some cases I'm guessing it's doing *more* work than that since it not only is converting 60 to 120, but doing interpolation so the frames aren't just duplicates but on-the-fly generated "in between" frames. That sounds harder to do than just taking 120 unique frames and passing them along untouched...

Again, aside from a DVI-D port and a seemingly minor change to the logic board, I'm *really* curious what else would need to be changed!?

a refresh rate is only emulated to be compatible with hardware we use to use with CRTs. LCDs flip frames like a slide show almost. It don't refresh it by use of a electron gun.

 

[snuuggles]

LCDs don't have a refresh rate. They're not CRTs. So 60mhz and 120mhz will look the same if you watch tv. To work out a LCDs real emulated refresh rate
1000/response time

Sure, I mean that's kind of semantics though, isn't it? The real point is that the pixels themselves are *capable* of displaying something unique 120 times a second. The fact that some logic board is sending duplicate data (or, not sending a change message) is the point. I suspect (but don't know) that there is some relatively cheap way that the manufacturers could provide a "120hz pass through", just provide a port with the bandwidth, and ask the logic board (or whatever is in there) to do *less* work by just passing the signel along uninterpolated/unduplicated.

Am I way off? Is there something I'm really mis-understanding?

 

[LiuKangBakinPie]

Sure, I mean that's kind of semantics though, isn't it? The real point is that the pixels themselves are *capable* of displaying something unique 120 times a second. The fact that some logic board is sending duplicate data (or, not sending a change message) is the point. I suspect (but don't know) that there is some relatively cheap way that the manufacturers could provide a "120hz pass through", just provide a port with the bandwidth, and ask the logic board (or whatever is in there) to do *less* work by just passing the signel along uninterpolated/unduplicated.

Am I way off? Is there something I'm really mis-understanding?

why? Again it doesn't have a refresh rate. 120mhz and 60mhz watching porn will look the same. ITS ONLY THERE WHEN YOU WAY TO HOOK IT UP WITH SOMETHING LIKE A GPU. THAT'S WHY.

 

[Sentry2]

Hmmm, so I'm not really sure what you mean. I know that so-called "120hz" TVs don't accept a 120hz input, but they *do* refresh 120 times a second.

Logically, there's a certain part of the TV that switches the 60hz input to 120hz. Now, what it actually *sends* may not be more than a duplicate image every other frame, but the pixels themselves don't know that. All they do is update 120 times a second with whatever is sent to them.

I'm assuming there's a logic board in there that makes the swap-over, and that since it's *already* sending 120 signals a second to the ~2 million pixels (which I'm calling the panel, but I'm not sure that's correct), why not allow it to send 120 unique signals rather than 60 unique signales joined by 60 duplicates (geez, in some cases I'm guessing it's doing *more* work than that since it not only is converting 60 to 120, but doing interpolation so the frames aren't just duplicates but on-the-fly generated "in between" frames. That sounds harder to do than just taking 120 unique frames and passing them along untouched...

Again, aside from a DVI-D port and a seemingly minor change to the logic board, I'm *really* curious what else would need to be changed!?

I stand corrected. I'm not really sure what's going on anymore. It sounds like the pixels in a 120Hz panel will refresh at 120Hz all the time(no matter what) but without a true 120Hz input source it just up converts(if you can call it that)...or doubles each frame of the 60Hz source. I just wonder why in the hell we don't have any 120Hz IPS monitors if some TV panels(IPS/VA usually) can display 120 fps regardless of the fact they can't accept anything over 60. I thought the argument was that IPS/VA tech was too slow to properly implement into pc monitors and that's why we are stuck with TN panels in 120Hz monitors...

 

[Athadeus]

It would require management pulling their heads out of their butts and getting sales to realize what consumers want, and communicating that to engineering. It would also require consumers to stop buying the low end stuff as much.

I need to find out if I can replace a board in my TCP50G15 with a new one to get it to have that packed frame 60hz 3D capable deal (though in seriousness, I'm sure I'll replace it before I am interested in 3D).

 

[LiuKangBakinPie]

I stand corrected. I'm not really sure what's going on anymore. It sounds like the pixels in a 120Hz panel will refresh at 120Hz all the time(no matter what) but without a true 120Hz input source it just up converts(if you can call it that)...or doubles each frame of the 60Hz source. I just wonder why in the hell we don't have any 120Hz IPS monitors if some TV panels(IPS/VA usually) can display 120 fps regardless of the fact they can't accept anything over 60. I thought the argument was that IPS/VA tech was too slow to properly implement into pc monitors and that's why we are stuck with TN panels in 120Hz monitors...

response rate not refresh rate.
And they make use of certain technologies to boost power so that can happen. It differs from manufacturer to manufacturer

 

[snuuggles]

response rate not refresh rate.
And they make use of certain technologies to boost power so that can happen. It differs from manufacturer to manufacturer

Forgive me, I feel I'm not understanding this particular differentiation.

Maybe if I break out what I'm asking into distinct items it would be easier for me to understand.

Again, with the understanding that I don't know *any* of this for sure, here's my guess how the 120hz TVs work:

1. pixels themselves wait for a change signal. Any one of them could be asked to change up to 120 times per second. Thus, this is why they are not lying when they call the TV "120hz".

2. The change signals are sent by a logic board or set of chips. This board most likely has some sort of frame buffer so it can compare the frame it just sent with the new one it's about to send, and tell the correct pixels to change (I think this is what you are saying, it's not that *every pixel* gets 120 signals per second, only the one's that need to change get sent a signal. OTOH that still means that each pixel *could* change 120 times per second *if the logic board sent them all a change signal*.)

3. This frame buffer is filled 60 times per second by the input at the back of the TV (the source). The logic board must then figure out what to do between inputs from the back of the TV. So 60 times per second it gets a whole fresh frame from the source, and it can just compare what is up on the screen at the time with what it just got and send the appropriate signals to the pixels that need changing. But between those 60 signals it's getting, it must "make up" a new frame, and compare *that* to what's on the screen and send along change signals to the pixels that need changing. In many (most?) cases, this "made up" frame is just a complete duplicate, and thus there is no need to send a change signal to any pixel, but in certain settings, it will try to interpolate what came before with what is coming next (so maybe the frame buffer is 3 or more frames), and try to "average" the pixels. That's why it smooths stuff out in certain settings (while adding input lag, it's got to wait for a couple of frames from the source so it knows what it's averaging).

So assuming I'm in the ballpark generally, it seems to me like it would be *easier* to make a logic board that would just expect a fresh new signal 120 times per second and simply compare old and new, and send along the change signals to the pixels needing the change. This would eliminate the board needing to collect multiple frames for interpolation/averaging.

Dunno if I'm missing something, please feel free to correct my logic, of course I really have no idea what's going on in there

 

[wahdangun]

As far as I know, there are no TVs on the market today that will actually accept and display 120hz signal from a computer.

Given that the new TVs have hdmi 1.4, and the old TVs *could have had* DVI-D ports, and that many of them already have a 120hz panel, what exactly was/is stopping the manufacturers from just providing the ability to use 120h as a real refresh.

It's been frusterating getting a good large-format screen that has truely good motion resolution. I've been trying out a 42" plasma, but 1. It's a little large for me, I'd prefer 32/37. 2. it buzzes and 3. it's not 120hz.

I can see why large-format "monitors" are not being made at 120hz, the larger monitors would be difficult to market with 1080p, and nothing but displayport will allow for higher resolutions @120hz.

But it's just weird to me that *not one TV manufacturer* has slapped a DVI-D port on thier 120hz tv and called it a "gamerz fury edition". Or something like that...

because HDMI doesn't have enough bandwidth to support 120Hz (and thats why the 3D over HDMI is limited to 24 FPS per eye @1080P) you need at least dual link DVI or DP

 

[bunnyfubbles]

it would require TVs with an interface that has enough bandwidth such as dual link DVI or Display Port, HDMI can't do it

as well as a large enough consumer base that was knowledgeable enough to create enough demand for such a product, which just isn't going to happen

 

[pcm81]

You will still only see the same frame rate as your source signal supports and if you have 1000FPS video card output rendering ability, this does not mean that the DVI or HDMI link between the card and monitor will support it... 120Hz works with 24, 30 and 60 FPS streams, because it divides evenly by all of them. However your pictuare actually changes only as fast as your data is transfered to the screen via HDMI or DVI cable. The FPS on the cable depends on resolution of each frame, because cables are bandwidth capped. For example 720p24 and 1080i30 take about the same amount of bandwidth... Your screen will never show 56fps, it will only refresh at its base modes, 24hz, 30hz, 60, 120hz, 600hz (Plasma)

 

[wahdangun]

You will still only see the same frame rate as your source signal supports and if you have 1000FPS video card output rendering ability, this does not mean that the DVI or HDMI link between the card and monitor will support it... 120Hz works with 24, 30 and 60 FPS streams, because it divides evenly by all of them. However your pictuare actually changes only as fast as your data is transfered to the screen via HDMI or DVI cable. The FPS on the cable depends on resolution of each frame, because cables are bandwidth capped. For example 720p24 and 1080i30 take about the same amount of bandwidth... Your screen will never show 56fps, it will only refresh at its base modes, 24hz, 30hz, 60, 120hz, 600hz (Plasma)

yes it can, thats why we turn on vsync for high FPS games because it can make screen tearing

btw have you ever tried 120 hz monitor ? its feel smother because the display can churn out 120 FPS when vsynic is on versus just 60 FPS on 60 hz

 

[OILFIELDTRASH]

I think all panels are basically the same. I believe it's the hardware behind the panel that differentiates a 120hz vs 60hz. So I don't believe even having the dual link dvi would make a difference.

 

[pcm81]

yes it can, thats why we turn on vsync for high FPS games because it can make screen tearing

btw have you ever tried 120 hz monitor ? its feel smother because the display can churn out 120 FPS when vsynic is on versus just 60 FPS on 60 hz

Except it works the other way around. It caps your video card at screens supported rates...

http://www.tweakguides.com/Graphics_9.html

 

[snuuggles]

I think all panels are basically the same. I believe it's the hardware behind the panel that differentiates a 120hz vs 60hz. So I don't believe even having the dual link dvi would make a difference.

Exactly. I am just wondering what else (besides the DVI-D or hdmi 1.4a port) would be required.

I mean, let's just say you had a hdmi 1.4a port and you were feeding it either a 60hz or 120hz signal. I contend that it would require *more* work and cost to have the logic board send an interpolated 120hz signal built from the 60hz signal, than it would cost to have it just send the 120hz signal.

I feel like a couple of people here are saying the panel couldn't actually display 120 unique frames per second. This is demonstrably false - the pixels are capable of being updated 120 times per second, period. Thus the issue is *what* they are being sent.

Let me put it another way, I know there are a couple of TVs that *will* accept a 120hz signal from a computer, but what they do is ignore half the frames, and actually re-build interpolated frames to send to the panel.

so it goes:
120hz->logic board ignores half the frames and interpolates from the other half of the frames back to 120hz->panel gets 120hz signal

It seems rediculous to say that there would be much additional cost to have it just accept the full bandwidth signal and pass it along to the panel.

Edit: When I say "I know" there are a couple of tvs that will accept a 120hz signal, what I mean is that I've read on several forums that people who have purchased new TVs with HDMI 1.4a ports have been told that it "accepts 120hz signal". But it turns out that while it would *accept* the signal, it wouldn't actually pass it along to the panel, it would instead downgrade it to 60hz, then interpolate it back up to 120hz. LAME!

 

[snuuggles]

it would require TVs with an interface that has enough bandwidth such as dual link DVI or Display Port, HDMI can't do it

as well as a large enough consumer base that was knowledgeable enough to create enough demand for such a product, which just isn't going to happen

Huh, I thought that 1.4a hdmi would support that bandwidth. I just noticed I forgot the 'a' in my OP though. But would you agree that 1.4a hdmi will support this bandwidth?

 

[OILFIELDTRASH]

Exactly. I am just wondering what else (besides the DVI-D or hdmi 1.4a port) would be required.

I mean, let's just say you had a hdmi 1.4a port and you were feeding it either a 60hz or 120hz signal. I contend that it would require *more* work and cost to have the logic board send an interpolated 120hz signal built from the 60hz signal, than it would cost to have it just send the 120hz signal.

I feel like a couple of people here are saying the panel couldn't actually display 120 unique frames per second. This is demonstrably false - the pixels are capable of being updated 120 times per second, period. Thus the issue is *what* they are being sent.

Let me put it another way, I know there are a couple of TVs that *will* accept a 120hz signal from a computer, but what they do is ignore half the frames, and actually re-build interpolated frames to send to the panel.

so it goes:
120hz->logic board ignores half the frames and interpolates from the other half of the frames back to 120hz->panel gets 120hz signal

It seems rediculous to say that there would be much additional cost to have it just accept the full bandwidth signal and pass it along to the panel.

Edit: When I say "I know" there are a couple of tvs that will accept a 120hz signal, what I mean is that I've read on several forums that people who have purchased new TVs with HDMI 1.4a ports have been told that it "accepts 120hz signal". But it turns out that while it would *accept* the signal, it wouldn't actually pass it along to the panel, it would instead downgrade it to 60hz, then interpolate it back up to 120hz. LAME!

I get what you're saying but it's too late for that. Ps3, xbox, blu rays all output at 60hz. We are just a niche market they couldn't care less about.

 

[snuuggles]

I get what you're saying but it's too late for that. Ps3, xbox, blu rays all output at 60hz. We are just a niche market they couldn't care less about.

Sure, I agree, but if it would cost them like <$20 to allow true 120hz input, seems like it's only a matter of time before *someone* just adds it for the heck of it... I mean, they still include a VGA connector on these things, just drop that relic and add DVI-D, done!

 

[wahdangun]

I think all panels are basically the same. I believe it's the hardware behind the panel that differentiates a 120hz vs 60hz. So I don't believe even having the dual link dvi would make a difference.

yes it is, if hdmi was not a problem why nvdia insist using it even tough it blocked the vent, i mean they can just use 4 hdmi port and include 4 hdmi to dvi converter that why it won't blocked the vent, improve cooling performance and maybe make the card more quite because its reduce.

 

[snuuggles]

yes it is, if hdmi was not a problem why nvdia insist using it even tough it blocked the vent, i mean they can just use 4 hdmi port and include 4 hdmi to dvi converter that why it won't blocked the vent, improve cooling performance and maybe make the card more quite because its reduce.

The same could be said for displayport though. Maybe there's a licensing cost to the other two? Or maybe they like that you can secure the cable to the card... Who knows.

 

[Wardrop]

Jesus Christ, just reading this from a Google search. Snuggles, I admire how you handled "LiuKangBakinPie". Reading his responses frustrated the crap out of me. I don't usually call people names on the internet, but what an arse. Didn't come close to answering your question despite seeming to know exactly what you were asking for. I would have dismissed anything he said however as soon as I saw his persistant use of "mhz" instead of "hz", which helps explain why he harped on so much about the difference between refresh rate and response time, despite the fact that they're effectively the EXACT SAME THING. An insecure arse trying to portray himself as being more knowledge than he actually is, wasting everyone's time in the mean time. Just look at the length of your replies to him. Feel sorry for you having to deal with that shit.

Anyway, I too have been wondering this. TV manufacturers shit me. Why do they insist on scaling ALL digital input, why not just do 1-to-1 by default. Why didn't this shit die out with analog. My second gripe with TV manufacturers is there ignorance to the computer monitor world, and the fact that people plug computers and other computer-based devices into their TV's - devices which turn off the graphics card output to power save, but no, stupid TV's insist on showing the "No signal" message with no way to force them to actually take a hint and go into power saving mode like any monitor would. Finally, the 120hz annoys me. I spent extra on my TV 4 years ago to get the "100hz/120hz" TV because I thought no one in their right mind would produce a panel capable of refreshing 120 times per second and not take a 120hz input.

 

[nenforcer]

Most modern digital / HD TV's have an option to put the panel / display in a "Just Scan" mode, which once again makes the dumb "monitors" which is what they should be and lets the display device handle all scaling and refreshing.