How is Hz scaling with different resolutions?

Talk about overclocking displays at a higher refresh rate. This includes homebrew, 165Hz, QNIX, Catleap, Overlord Tempest, SEIKI displays, certain HDTVs, and other overclockable displays.
Max
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How is Hz scaling with different resolutions?

Post by Max » 04 Jul 2014, 19:46

So I'm looking to get a new monitor, I'd like to be able to have a high refresh rate for games like counter strike and then high resolution/lower refresh rate for fps capped games, and just more casual games in general.

Also please correct me if I get any of this terminology wrong I'm new here and don't want to be new forever. :oops:

With 2160p60hz monitors starting to become more and more reasonably priced, would it make sense for me to get a 4k monitor? I've been thinking about how the scaling should work with monitors but I don't know if it actually works this way so I'm hoping someone could help me out :?.

So if 1080p is 1/4 the pixels of 2160p would a 2160p60Hz monitor be able to do 240Hz at 1080p?

There is a thread on overclockers.net where a guy was able to get his Seiki 39inch to do:

3840x2160 @ 33Hz
3200x1800 @ 47Hz
2560x1440 @ 72Hz
1920x1080 @ 125Hz

graphed*:
seiki 39 oc graphed.png
seiki 39 oc graphed.png (9.87 KiB) Viewed 6296 times
*rounded to nearest 10 and yes that's notepad. :lol:

I think that this shows the scaling that I'm talking about but I also realize that for the Seiki monitor, it's a bit odd since it seems to be hitting the limit for hdmi...

So ill just run through the math for what should be the theoretical highest Hz for the Seiki monitor at different resolutions according to the logic I started this topic with...
3840*2160= 8294400
3200*1800= 5760000
8294400/5760000= 1.44
33hz*1.44= 47Hz

theoretical if 2160p@33Hz:
1800p = 47Hz
1440p = 74Hz
1080p = 132Hz

So obviously there is a discrepancy between the theoretical Hz at different resolutions and the real world Hz.

If you could get a 2160p60Hz monitor to 64Hz theoretically you should be able to get 1440p144Hz But if you consider how the Seiki monitor scaled to 1440p the real world Hz should be about 138Hz.

My questions are:
How well do 2160p60Hz monitors scale, and has anyone tried overclocking a 2160p60Hz monitor?

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RealNC
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Re: How is Hz scaling with different resolutions?

Post by RealNC » 04 Jul 2014, 20:20

Short answer: it depends on the monitor.

Long answer: If the monitor doesn't have an overclocking lock, you can do all that if the panel actually supports the high refresh rates. Just like normal 1080p 60Hz monitors. You can try to overlock them, but it's not guaranteed to work. Mine for example only goes up to 77Hz. Other will go above that, but will start to skip frames. And others will work just fine when overclocked. Same goes for 4K monitors. You can try to OC their panels. Some monitors can take it, others can't.
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Max
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Re: How is Hz scaling with different resolutions?

Post by Max » 04 Jul 2014, 21:08

RealNC wrote:Short answer: it depends on the monitor.

Long answer: If the monitor doesn't have an overclocking lock, you can do all that if the panel actually supports the high refresh rates. Just like normal 1080p 60Hz monitors. You can try to overlock them, but it's not guaranteed to work. Mine for example only goes up to 77Hz. Other will go above that, but will start to skip frames. And others will work just fine when overclocked. Same goes for 4K monitors. You can try to OC their panels. Some monitors can take it, others can't.
Are you saying that your monitor for couldnt go higher than 77Hz at a lower resolution? Because from what I understand with monitors they have a (I don't know if this is the right word) bandwidth limit so for example if you wanted higher than 77Hz on your monitor you would have to go with a lower resolution is that not true?

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Re: How is Hz scaling with different resolutions?

Post by Q83Ia7ta » 04 Jul 2014, 21:38

Almost all monitors won't just accept higher refresh rates by firmware. Seiki isn't monitor vendor. And as new player of TV business i guess they have less human resources and that's why they didn't block overclocking by firmware. May be I'm wrong. Just look at 120/144Hz monitors: none accepts higher refresh rates at lower resolution. For example: http://forums.blurbusters.com/viewtopic.php?f=4&t=835

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Re: How is Hz scaling with different resolutions?

Post by Max » 04 Jul 2014, 22:08

Q83Ia7ta wrote:Almost all monitors won't just accept higher refresh rates by firmware. Seiki isn't monitor vendor. And as new player of TV business i guess they have less human resources and that's why they didn't block overclocking by firmware. May be I'm wrong. Just look at 120/144Hz monitors: none accepts higher refresh rates at lower resolution. For example: http://forums.blurbusters.com/viewtopic.php?f=4&t=835
A monitor being locked for overclocking is defiantly a concern for me and something I'm aware of. The current 2160p60 monitors that I'd be interested in getting are all made by popular companys: Dell, Samsung, Asus, and Philips. I know the Samsung one is locked since they seem to lock all of their monitors. Speaking of which my current monitor is made by Samsung and is locked at 80Hz even though it can handle more than that.

I looked at the topic you linked, I think what Chief Blur Buster said kind of confirms what I was talking about though.
"3. No, and no. The limiting factor is dotclock (number of pixels refreshed per second..."
I think that at least in theory with out the monitor being locked lowering the resolution (reducing the amount of pixels) will allow you to increase the Hz (times the pixels are refreshed). Maybe I'm completely wrong but I don't think so because the Seiki monitor does seem to confirm what I'm thinking at least in principal. But then again the Seiki monitor is weird in that the HDMI bus is a limiting factor and that its native 120Hz.

I'm pretty sure back in the day people used to lower the resolution on their CRT monitors to get higher Hz. I don't think that's necessarily relevant though.

Also has anyone tried to overclock a 4k monitor (besides the Seiki 39in) at lower resolutions or a 1440p monitor at lower resolutions?

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Re: How is Hz scaling with different resolutions?

Post by Q83Ia7ta » 04 Jul 2014, 23:26

Max wrote:I looked at the topic you linked, I think what Chief Blur Buster said kind of confirms what I was talking about though.
"3. No, and no. The limiting factor is dotclock (number of pixels refreshed per second..."
I think that at least in theory with out the monitor being locked lowering the resolution (reducing the amount of pixels) will allow you to increase the Hz (times the pixels are refreshed). Maybe I'm completely wrong but I don't think so because the Seiki monitor does seem to confirm what I'm thinking at least in principal. But then again the Seiki monitor is weird in that the HDMI bus is a limiting factor and that its native 120Hz.
dotclock or pixel clock can be unlocked via patching drivers. http://www.monitortests.com/forum/Threa ... ck-Patcher but it's not only the one limiting factor. People use that patcher mainly to get 96-120Hz on korean 2560x1440p monitors.
Seiki somehow made HDMI work like DVI. Look at OSD:
http://www.avsforum.com/photopost/data/ ... 0x224.jpeg
http://www.blurbusters.com/wp-content/u ... 00x207.jpg
Max wrote:I'm pretty sure back in the day people used to lower the resolution on their CRT monitors to get higher Hz. I don't think that's necessarily relevant though.
Yes but it's CRT and one of the main limiting factor was http://en.wikipedia.org/wiki/Horizontal_scan_rate
Max wrote:Also has anyone tried to overclock a 4k monitor (besides the Seiki 39in) at lower resolutions or a 1440p monitor at lower resolutions?
Anyone has overclocked 27" 1080p 144Hz monitor to 240Hz. But he made hardware and firmware changes
http://forums.blurbusters.com/viewtopic.php?f=7&t=48

After some googling I'm alomost sure limiting factors can be:
1. Just firmware. For example don't accept refresh rate higher than X.
2. T-CON - timing controller.
3. Main board.
4. Panel speed.

For 2 & 3 there is also example: As mentioned about people use pixel clock patcher mainly to get 96-120Hz on korean 2560x1440p and at same time their monitors PCB must be exactly like this:
http://overlordcomputer.com/products/overlord-pcb-set
http://i.imgur.com/m2tsA.jpg

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Re: How is Hz scaling with different resolutions?

Post by Max » 04 Jul 2014, 23:56

Anyone has overclocked 27" 1080p 144Hz monitor to 240Hz. But he made hardware and firmware changes
viewtopic.php?f=7&t=48
Ok that's pretty interesting but I was wondering if anyone has lowered the resolution to increase the Hz on a 1440p monitor like from 1440p to 720p.
After some googling I'm alomost sure limiting factors can be:
1. Just firmware. For example don't accept refresh rate higher than X.
2. T-CON - timing controller.
3. Main board.
4. Panel speed.

For 2 & 3 there is also example: As mentioned about people use pixel clock patcher mainly to get 96-120Hz on korean 2560x1440p and at same time their monitors PCB must be exactly like this:
http://overlordcomputer.com/products/overlord-pcb-set
http://i.imgur.com/m2tsA.jpg
I agree with you on what could be the limiting factors but, I would think that if you lower the resolution to compensate for higher Hz, you wouldn't need more bandwidth so that could leave just the firmware, t-con and the panel as the limiting factors.

Also I wouldn't be surprised if a lot of 60Hz 4k monitors are using a timing controller similar to one off of a 120/144Hz 1440p monitor, since they already exist and 2160p60Hz seems fairly similar to 1440p144Hz.

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Re: How is Hz scaling with different resolutions?

Post by RealNC » 05 Jul 2014, 06:38

Just because a panel has higher resolution doesn't mean it can support higher refresh. That's because TFT only support one resolution.

A 4K panel only operates at 4K. If you choose a 1080p resolution on a 4K panel, 1080p is going to get upscaled to 4K. TFT panels only have one resolution. Every other resolution is getting upscaled to the panel's resolution.

CRT monitors do work the way you describe. If you lower the resolution, you can increase the refresh rate. On a TFT, you *cannot* lower the resolution. There's only one resolution supported. If the panel is 60Hz by spec, but can support more than 60Hz, then you can try to OC it. At which resolution you're trying to OC doesn't matter for the panel. That's only important for the parts that handle the signal transmission.
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Re: How is Hz scaling with different resolutions?

Post by Max » 05 Jul 2014, 18:48

RealNC wrote:Just because a panel has higher resolution doesn't mean it can support higher refresh. That's because TFT only support one resolution.

A 4K panel only operates at 4K. If you choose a 1080p resolution on a 4K panel, 1080p is going to get upscaled to 4K. TFT panels only have one resolution. Every other resolution is getting upscaled to the panel's resolution.

CRT monitors do work the way you describe. If you lower the resolution, you can increase the refresh rate. On a TFT, you *cannot* lower the resolution. There's only one resolution supported. If the panel is 60Hz by spec, but can support more than 60Hz, then you can try to OC it. At which resolution you're trying to OC doesn't matter for the panel. That's only important for the parts that handle the signal transmission.
Yes but because monitors have a limit of how much bandwidth they have for the signal, lowering the resolution should allow for higher Hz. That's assuming the other parts of the monitor can handle it, you should have read the other posts so far.

And I still want to know how well Hz scales with lower resolutions :(

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Re: How is Hz scaling with different resolutions?

Post by RealNC » 05 Jul 2014, 21:31

Max wrote:Yes but because monitors have a limit of how much bandwidth they have for the signal, lowering the resolution should allow for higher Hz.
That doesn't mean the panel can show higher Hz.
And I still want to know how well Hz scales with lower resolutions :(
There are no limits. You can raise the timings as you please. You can run a 4K resolution at 100Hz, if you want. Whether the monitor can handle that or something will blow up in smoke, is another question. It depends on how overclockable the monitor is.
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