Seeking clarification on OLED / BFI...some beginner questions

[O-T-T]

Hi everyone!

With the announcement of a lot of new models for 2024 I think the time has come for me too to get on the OLED hype train.
I have some questions that I would like to bring to the attention of the expert members of this forum, both to help me choose the right model for my needs and to clarify some doubts regarding motion blur reduction: probably many of these are silly questions since I'm a newbie...so please be patient. Simple and direct answers are fine, even a YES/NO in many cases should be sufficient

Premise:

I would like to use the monitor mainly for retrogaming, especially for emulation with RetroArch
I would like to use BFI but from what I have read it seems that the models with Samsung QD-OLED panel will not have this feature, while at the moment among those equipped with LG's WOLED panel only Asus seems to have implemented BFI but with fixed refresh at 120hz...which if I understand correctly is practically useless for retrogaming and in any case it would not fully exploit the potential of the monitor

At the moment I would be oriented towards 4K@240hz but I would also like to understand if it might be worth sacrificing the resolution to have a much higher refresh (QHD @360hz or 480hz)this is one of the most uncertain points for me, because I really care about having a motion clarity as close as possible to that of a CRT but I would also like the image to be a faithful reproduction of how the games looked on CRT and for this reason shaders and high resolution are important, while I know that QHD may not give as good results in this sense compared to 4K.

Here we go:

1) I read about RetroTINK 4K and its numerous features including BFI: if I understood correctly, however, the device only serves as an upscaler for real consoles or in any case signal sources up to 1080p, therefore it CANNOT be used in conjunction with a PC for retrogame emulation to add BFI to a monitor that doesn't have it, is that correct?

2) If 1) is correct, are there any devices on the market that implement BFI on a monitor via external hardware without being an upscaler?
I'm only interested in the BFI functionality...if such a device doesn't exist, it should be quite simple to make one and certainly much less expensive than the RetroTINK 4K which has many other additional features (which I'm not interested in): could this be a good idea to suggest to the creator of RetroTINK? (@Chief)

3) If I understand correctly, a high refresh OLED (e.g. 480hz) would provide motion clarity almost at the level of a CRT if a frame rate equivalent to the monitor's max refresh was guaranteed: the problem is that retrogames run at 60hz, 50hz or in any case much below 480hz and the frame rate is sometimes even lower than the refresh rate. So the "solution" is BFI, which basically adds black frames. My question is: to reduce/cancel motion blur, wouldn't it be possible to apply a principle similar to BFI but instead of inserting black frames, duplicate (or triple, etc.) the game frames until the monitor's native refresh rate is reached? In other words, for a 480hz monitor, if a game originally features 60fps @ 60hz you couldn't multiply the frames 7 times and obtain the same motion blur reduction effect with the advantage of not losing brightness and/or having colors distortion? Then perhaps it would also eliminate the perception of flicker that the BFI presents, especially below 120hz, since the additional frame is not a black screen. Obviously if this hasn't been done so far and we've always talked only and exclusively about BFI I imagine there are many reasons why my suggestion is idiocy, I'd just like to know them to satisfy my curiosity

Thanks in advance to anyone who wants to answer me!

[O-T-T]

Hello Chief!

I see you replied in detail to the provocative post
However, no one so far has answered the questions I asked in my opening post (listed and numbered above): could you please help me with this?

Furthermore, reading what you wrote above, a few other questions came to mind, I'll take this opportunity to ask them here: again, very simple answers or even YES/NO would be plenty for me!

A) so, if I understand correctly, a 240hz refresh (+ BFI) on OLED is completely satisfactory for emulation/retrogaming (which is what I'm mainly interested in), in fact it is the maximum that can be obtained at the moment as going beyond that refresh (e.g. 480hz) brings no perceivable advantages for this type of application, is this correct?
I mean, certainly 480hz is better than 240hz and this has advantages but they are not perceptible in the retrogames scenario, if I understood what you wrote correctly. This point interests me particularly because all this time I have been torn between opting for a 4K 240hz or a QHD at 360/480hz: the first option would give me the best image quality, the perfect resolution for the shaders and furthermore the 4K models are equipped with more features (e.g. Dolby Vision, etc.) than QHD ones, but I was very excited about the 480hz, anticipating a possible super performance in terms of motion clarity even for retrogaming.

B) Is the BFI at 240hz flickering worse (=more annoying) than that of CRTs, or the same or better? I ask because flickering is literally the only aspect I don't miss about the CRT era

C) if the monitor is not equipped with a decently implemented hardware BFI or it comes with an useless one (for retrogaming) as it seems unfortunately the norm, the only way to obtain the "perfect" motion clarity we are talking about is to resort to a software BFI like the one integrated in RetroaArch? If I understand correctly, compared to a full featured hardware-BFI implementation, the RetroArch one does not allow you to set some parameters (I think the pulse width and some others I don't remember the names) and this translates into the impossibility of modulating the ratio between motion blur reduction and brightness reduction, is this correct? In other words, RA BFI only allows you to get maximum blur reduction but also implies maximum brightness reduction, right? There are better alternatives?

D) is it that difficult to implement a BFI that works with VRR? If I understand correctly, this possibility does not exist at the moment. The problem is that it can only be obtained with a hardware-BFI, which allows you to vary the particular parameters I mentioned above, is that right? If so, unless some manufacturers decide to take the time to work on this we will never see it...

E) Out of curiosity, how a 240hz OLED + BFI compare to NVIDIA ULMB2 or Pulsar strobing for LCD? I mean, can you complete this equation: 240hz OLED + BFI = ???hz LCD + Pulsar

Thanks!!!

[Chief Blur Buster]

I just split the completely offtopic sidetrack (discussion between me and Supermodel_Evelynn) to
Controversial Debate: Is 360Hz Worth It?.

[O-T-T]

I just split the provocative parts (discussion between me and Supermodel_Evelynn) to Controversial Debate: Is 360Hz Worth It?.

Ok

I'm waiting for your reply to my questions, then. Of course, when you get the time/are willing to. Thanks again!

[Chief Blur Buster]

I am assuming you're looking for an OLED monitor. There are no sub-$1000 27" desktop-monitor OLEDs less than 240Hz, so you can treat them as luxury 120Hz, 180Hz, 240Hz displays (NTSC) and 100Hz, 150Hz, 200Hz displays (PAL). Or even 54Hz (Mortal Kombat). All the OLEDs can support custom refresh rates fortunately.

A) Yes.

You have no choice but to get 240Hz if you're wanting a 27" OLED monitor for a desk. They never came at 120Hz at sub-$1000 prices, so the extra Hz is a bonus. The quality of both WOLED and QD-OLED are both fantastic for emulation, with excellent blacks for your Pac Man / Defender early retro games with lots of blacks. And excellent motion handling (from 120-240Hz+BFI) for fast scrolling games like Sonic Hedgehog.

Most retro games are fine at 120Hz+BFI and 180Hz+BFI but some fast VSYNC ON framerate=Hz scrollers like Sonic Hedgehog work quite very human-noticeably better with 240Hz+BFI. Whether you run them at 120, 180, or 240 is irrelevant, the OLED displays are currently fantastic retrogaming displays much closer to CRTs than LCDs were (whether 120Hz+BFI for slow content, or 240Hz+BFI for fast Sonic Hedgehog content). The large amounts of retro games that use black backgrounds, means any OLED display of any refresh rate, automatically looks better; the extra refresh rate is a quite noticeable bonus.

B1) Depends on the resolution of your gaming

If your retro content is 480p or less, then 240Hz is sufficient for most retrogaming needs.
As a rule of thumb, most OLED looks clear up to (2 x MaxHz) pixels/sec with or without BFI

240Hz OLED = Very clear scrolling up to 480 pixels/sec
360Hz OLED = Very clear scrolling up to 720 pixels/sec
480Hz OLED = Very clear scrolling up to 960 pixels/sec

Since retro content is low resolution, those covers most retrogaming scrolling needs.

Assuming minimum possible blur:
- Framerate-based blur reduction: framerate=MaxHz (maximally achieved during VSYNC ON)
- BFI/Strobe-based blur reduction: Visible frame is 1/MaxHz flash

240 vs 480Hz will not matter for the low resolution of retrogames much, but it will give you more adjustability of motion blur (see TestUFO Variable Persistence BFI. If you play high resolution content at high frame rates, and want the improved motion quality of panning/turning/scrolling, it is noticeable if you eye-track the screen movements. Super smooth-scrolls (e.g. mousewheel scrolling in browser, not dragging scrollbar) actually looks beautiful on OLED, anything that's not obscured by mouse smoothness limitations (mouse jitter).

B2) Rabbit hole alert, Yes-ish and No-ish

- BFI on OLEDs flicker less than LCD strobing.
- BFI may or may not flicker more than CRTs, depending on how the BFI is configured.
Example, the different UFOs flicker differently at TestUFO Variable Persistence BFI (don't view this on 60Hz, borrow a 240Hz display to view this animation)

C) Software BFI actually looks very good on OLED

Fortunately software BFI and hardware BFI can look good, and sometimes software BFI looks better than hardware BFI on OLEDs. Retroarch supports command line options for BFI.

And, the Retrotink 4K can convert SDR->HDR and brightness-boost the BFI, and do BFI at lower latency than the BFI built into televisions. However, it can't do 1440p240Hz, unless you reduce resolution (e.g. 2560x720 or 1280x1440 or such odd resolutions). But the 'Tink can do 240Hz BFI output with CRT masks, as long as you're feeding it a fairly low resolution.

D) It's theoretically possible, but it's a big reply rabbit hole

E) LCDs far outperform OLED BFI for high resolutio content, but for retrogaming, it's not critical

Depends on content. If you use high resolution framerate=Hz VSYNC ON content involving super fast motion (fast panning, scrolling, turning) that does not have mouse-jitter/mouse-microstutter weak links -- then strobing can be literally 10x clearer motion than OLED, but it's not important for the low-resolution of retrogaming. The quality of BFI for retrogaming is better, but if you need esports gaming, strobing can look better.

120Hz BFI = ~50% blur reduction for 60fps
240Hz BFI = ~75% blur reduction for 60fps
ULMB/etc = ~90% blur reduction for framerate=Hz (ULMB doesn't always support 60fps)

The OLED HDR + blacks + more than outweighs the vastly better motion blur reduction of LCD strobe backlights.
GSYNC Pulsar looked amazing to my eyes, though, if you want lots of mixed content.

I am negotiating with NVIDIA behind the scenes for a configurable min-Hz strobe threshold for GSYNC Pulsar, to include retrogaming uses, so keep tuned on that. But OLED BFI flickers less than 60Hz ULMB/Pulsar, if you're concerned about that. Not everyone is sensitive.

[O-T-T]

I am assuming you're looking for an OLED monitor.

It's correct. And yes, I'd like to get a 32" 4K OLED even if it's "only" 240hz, unless the 27" QHD @480hz offers an important and perceptible difference regarding motion clarity/blur reduction...which you kindly confirmed to me is not the case for retrogaming (which is the application I care the most when I talk about motion clarity).

B1) Depends on the resolution of your gaming

If your retro content is 480p or less, then 240Hz is sufficient for most retrogaming needs.
As a rule of thumb, most OLED looks clear up to (2 x MaxHz) pixels/sec with or without BFI

240Hz OLED = Very clear scrolling up to 480 pixels/sec
360Hz OLED = Very clear scrolling up to 720 pixels/sec
480Hz OLED = Very clear scrolling up to 960 pixels/sec

Since retro content is low resolution, those covers most retrogaming scrolling needs.

Perfect! This is what I wanted to be confirmed, thanks!

240 vs 480Hz will not matter for the low resolution of retrogames much, but it will give you more adjustability of motion blur (see TestUFO Variable Persistence BFI. If you play high resolution content at high frame rates, and want the improved motion quality of panning/turning/scrolling, it is noticeable if you eye-track the screen movements. Super smooth-scrolls (e.g. mousewheel scrolling in browser, not dragging scrollbar) actually looks beautiful on OLED, anything that's not obscured by mouse smoothness limitations (mouse jitter).

Yeah, I know. If I understood your posts about this that I read on the forum, with 240hz I can get 75% blur reduction at max (with BFI) while with a 480hz panel I can get up to 87,5% blur reduction. It's clear that beyond 240hz the diminishing return (monitor refresh rate / BFI blur reduction ratio) become apparent and it escalates even more after 480hz. I think that 480hz is the golden theshold beyond which it is not worth investing until we wouldn't be able to reach 1000hz. I mean, to give an example, I think it's not worth buying a hypothetical 600hz monitor - which will certainly be offered at a very high price - to get 3% more blur reduction. You might as well wait directly for "the final monitor" at 1000hz. At least as far as retrogaming is concerned.

- BFI on OLEDs flicker less than LCD strobing.
- BFI may or may not flicker more than CRTs, depending on how the BFI is configured.

Gotcha. Thanks for the clarification!

Fortunately software BFI and hardware BFI can look good, and sometimes software BFI looks better than hardware BFI on OLEDs.

This surprises me! I thought hardware-BFI was inherently superior

And, the Retrotink 4K can convert SDR->HDR and brightness-boost the BFI, and do BFI at lower latency than the BFI built into televisions. However, it can't do 1440p240Hz, unless you reduce resolution (e.g. 2560x720 or 1280x1440 or such odd resolutions). But the 'Tink can do 240Hz BFI output with CRT masks, as long as you're feeding it a fairly low resolution.

Yes, I read a bit about RetroTINK: I asked about it in my op post, because I'm not sure it can be used in combination with a PC only as a BFI implementer (and possibly scanlines, etc.) for an exclusive application to retrogaming. I didn't understand if it only works with consoles or similar or if it can be connected to a PC. The 4K 60hz bandwith limit worries me: I think this implies that it cannot be used with modern games in 4K + fast panel (>60hz) but I don't understand if it can be good for retogaming or if it has limitations in some scenario for this application too.

Also, in the opening post I asked if there are devices on the market that allow to add BFI to a monitor but without all the scaler features (and cost!) of the RetroTINK. This is because I thought that a software-only implementation of the BFI was inferior to a hardware one or one generated by a specific external device... but I seem to understand from what you wrote that I was wrong, so there would really be no need/advantage in using an external device like RetroTINK for BFI only versus using a software BFI like the one built into RetroArch. Can you confirm?

E) LCDs far outperform OLED BFI for high resolutio content, but for retrogaming, it's not critical

Depends on content. If you use high resolution framerate=Hz VSYNC ON content involving super fast motion (fast panning, scrolling, turning) that does not have mouse-jitter/mouse-microstutter weak links -- then strobing can be literally 10x clearer motion than OLED, but it's not important for the low-resolution of retrogaming. The quality of BFI for retrogaming is better, but if you need esports gaming, strobing can look better.

Thank you again for this clarification.

120Hz BFI = ~50% blur reduction for 60fps
240Hz BFI = ~75% blur reduction for 60fps
ULMB/etc = ~90% blur reduction for framerate=Hz (ULMB doesn't always support 60fps)

The OLED HDR + blacks + more than outweighs the vastly better motion blur reduction of LCD strobe backlights.
GSYNC Pulsar looked amazing to my eyes, though, if you want lots of mixed content.

So ULMB 2/Pulsar give you about 90% blur reduction - basically with any IPS above 360hz I suppose - while to get the same result with OLED+BFI we need at least a 600hz panel, correct?

I am negotiating with NVIDIA behind the scenes for a configurable min-Hz strobe threshold for GSYNC Pulsar, to include retrogaming uses, so keep tuned on that. But OLED BFI flickers less than 60Hz ULMB/Pulsar, if you're concerned about that. Not everyone is sensitive.

Great news! And let me THANK YOU for your detailed answers and for the time you dedicated to my questions, I really appreciated.

[Chief Blur Buster]

B1) Depends on the resolution of your gaming

If your retro content is 480p or less, then 240Hz is sufficient for most retrogaming needs.
As a rule of thumb, most OLED looks clear up to (2 x MaxHz) pixels/sec with or without BFI

240Hz OLED = Very clear scrolling up to 480 pixels/sec
360Hz OLED = Very clear scrolling up to 720 pixels/sec
480Hz OLED = Very clear scrolling up to 960 pixels/sec

Since retro content is low resolution, those covers most retrogaming scrolling needs.

Perfect! This is what I wanted to be confirmed, thanks!

Be noted, this ideal case only occurs if:
...For non-BFI, you need framerate=MaxHz. 60fps looks same at 120/240/360/480 OLED without BFI. You must spray framerate to keep up with the Hz, if you want framerate-based motion blur reduction.
...For BFI, you need 1-visible-frame BFI. RetroArch indeeds supports this mode, so will follow this Blur Busters Law (even on the larger 'scaled' pixels).

[Chief Blur Buster]

This surprises me! I thought hardware-BFI was inherently superior

I thought so, until Mike & I achieved LESS LATENCY and a BRIGHTER PICTURE with the Retrotink 4K BFI than the LG TV Firmware BFI...

So, I successfully got software BFI outperforming hardware BFI on OLEDs, as long as you don't mind the resolution sacrifice.

Yes, I read a bit about RetroTINK: I asked about it in my op post, because I'm not sure it can be used in combination with a PC only as a BFI implementer (and possibly scanlines, etc.) for an exclusive application to retrogaming. I didn't understand if it only works with consoles or similar or if it can be connected to a PC. The 4K 60hz bandwith limit worries me: I think this implies that it cannot be used with modern games in 4K + fast panel (>60hz) but I don't understand if it can be good for retogaming or if it has limitations in some scenario for this application too.

Yes, you can use PC input into Retrotink 4K, but there's some edge cases involved. You can do 1080p60 input, 1080p120 output. Or 720p60 input, 720p240 or possibly 1080p240 output. There's RAM bandwidth limitations. There is a possible undocumented 4:2:2 or 4:2:0 chroma setting that may allow 1080p60 input, 1080p240 output. Also, the Retrotink 4K logo square on top is designed to be brute-removable if you want to heatsink the FPGA for overclocking in the future -- it's directly above the FPGA, giving you a template square for a heatsink+fan for Retrotink 4K overclocking.

You can't do 1080p60 input, 1080p240 output, today quite just yet apparently, but I heard they are trying to make that work through one or a combination of: 4:2:2 chroma + a bit of overclock. If this feature is super-important, join the Retrotink 4K discord and plead, plead, please Mike for that capability. So 1080p60 in, 1080p240 out, is a bit of a hacking-required endeavour.

The Tink was designed originally for low-rez material, so 1080p60 input is a bonus.

Also, in the opening post I asked if there are devices on the market that allow to add BFI to a monitor but without all the scaler features (and cost!) of the RetroTINK. This is because I thought that a software-only implementation of the BFI was inferior to a hardware one or one generated by a specific external device...

A box-in-middle is always software BFI but the hardware box means it can framepace the BFI perfectly.

However, Retroarch BFI can only framepace imperfectly at 240Hz, so there is a few problems with it.

[O-T-T]

B1) Depends on the resolution of your gaming

If your retro content is 480p or less, then 240Hz is sufficient for most retrogaming needs.
As a rule of thumb, most OLED looks clear up to (2 x MaxHz) pixels/sec with or without BFI

240Hz OLED = Very clear scrolling up to 480 pixels/sec
360Hz OLED = Very clear scrolling up to 720 pixels/sec
480Hz OLED = Very clear scrolling up to 960 pixels/sec

Since retro content is low resolution, those covers most retrogaming scrolling needs.

Perfect! This is what I wanted to be confirmed, thanks!

Be noted, this ideal case only occurs if:
...For non-BFI, you need framerate=MaxHz. 60fps looks same at 120/240/360/480 OLED without BFI. You must spray framerate to keep up with the Hz, if you want framerate-based motion blur reduction.
...For BFI, you need 1-visible-frame BFI. RetroArch indeeds supports this mode, so will follow this Blur Busters Law (even on the larger 'scaled' pixels).

Understood. I'm planning to use RetroArch + its internal BFI implementation, at least till something better is available.

The reason why I'm happy with what you told me is that I'm mainly interested in emulating arcades from the golden era (70s/80s) and home computers especially from the 80s. So the typical resolutions for HCs were 320x200 or 320x256 or in any case something in those limits (excluding interlaced resolutions, which were rarely used anyway, especially in games) while for arcades often even less.
Therefore the 480 pixels/sec threshold should be absolutely plenty for my (main) needs.

Of course I'd like to emulate some arcades and HC from the '90 too, but even in this case I'm not too worried about the 480 pixels/sec limit.

For consoles it could be different, but I should be covered at least up to fourth generation which is plenty for me: I've never been a big fan of consoles anyway, and the only one I still own is an original Neo-Geo purchased directly in Japan.

[O-T-T]

Yes, you can use PC input into Retrotink 4K, but there's some edge cases involved. You can do 1080p60 input, 1080p120 output. Or 720p60 input, 720p240 or possibly 1080p240 output. There's RAM bandwidth limitations. There is a possible undocumented 4:2:2 or 4:2:0 chroma setting that may allow 1080p60 input, 1080p240 output. Also, the Retrotink 4K logo square on top is designed to be brute-removable if you want to heatsink the FPGA for overclocking in the future -- it's directly above the FPGA, giving you a template square for a heatsink+fan for Retrotink 4K overclocking.

You can't do 1080p60 input, 1080p240 output, today quite just yet apparently, but I heard they are trying to make that work through one or a combination of: 4:2:2 chroma + a bit of overclock. If this feature is super-important, join the Retrotink 4K discord and plead, plead, please Mike for that capability. So 1080p60 in, 1080p240 out, is a bit of a hacking-required endeavour.

The Tink was designed originally for low-rez material, so 1080p60 input is a bonus.

So for my needs (see my previous post) what I need is a 480p output (the max I can use if I want the least motion blur possible) @ 240hz and RetroTINK can do that. Is it correct? Note that I'd like to get 4:4:4 chroma, since basically all CRT masks/shaders for RetroArch need it, otherwise artifacts of every kind should be expected.

So, RetroTINK can do 4:4:4 480p@240hz output?

Also, please bear with me because I don't understand much about these things and I have still many (silly?) doubts:

1) I must connect RetroTINK to the GPU via HDMI (I suppose) and then to the monitor, it is correct?
2) I need to feed RetroTINK with a low res signal: if I use RetroArch for emulation, the signal provided to RetroTINK is that of the emulated resolution/frequency or the one set in Windows? What happens to RetroTINK if/when I exit RA and go back to Windows Desktop?

A box-in-middle is always software BFI but the hardware box means it can framepace the BFI perfectly.

However, Retroarch BFI can only framepace imperfectly at 240Hz, so there is a few problems with it.

Ugh! I thought I understood that the software-BFI and even more so the RA-BFI (which allows you to vary some parameters) were practically perfect for OLEDs. Now you tell me that RA BFI has problems! What exactly? What kind of visual defects should I expect?

However, as I wrote in my opening post, it seems to me like a good idea to suggest to Mike that he seriously think about proposing a device with the sole exclusive functionality of implementing BFI and perhaps also CRT masks and the scanlines.

Basically, a RetroTINK without the scaler and the related functions: in this way you would have an incredibly attractive product for a vast area of users, making these precious features available but at a much lower price than the RetroTINK.

What do you think Chief? Can you tell Mike about this idea, since you work with him and know him well?