Feature request: High Refresh Picture By Picture with Gsync + backlight strobe

I honestly don’t know what would be the limitations of this (or if it’s even possible).

As you know, nvidia has officially killed off SLI support at the driver level for the only SLI capable card in the line up, the 3090. Currently the only way to actually use SLI in many games for the 3090 is to setup SLI with “surround view” in nvidia control panel which essentially allows us to connect 2 or more outputs from the SLI cards (can be 3090s, 2080s, 2080ti, any SLI card really) and essentially make each GPU render a different screen. In essence if you have 2 QHD monitors and you hook up 1 cable from each one to each GPU in SLI, that GPU will render half of whatever is being rendered for that game.

Currently I am aware certain gaming monitors support the Picture By Picture mode (locked to a specific refresh, usually 60 hz) where it can take 2 inputs and essentially compose two screens with each taking up half. The Samsung G7 32" and 27" have this feature for example and have allowed people with SLI configurations to actually render at higher frame rates simply because each GPU is rendering half the screen. On a QHD screen that would mean each GPU in SLI would have to render a resolution of 1280x720 each or 1920x1080 for the 4k eve model. Currently this is the only way to get anything close to SLI 3090 (unless the game explicitly supports explicit SLI) on a bigger library of games and get a decent performance uplift in older games that either don’t support DLSS or just flat out requires more power to run at high frame rates (I’m looking at you Ark: Survival evolved…old game that maxes my 3090 at QHD with all details maxed out!).

I hope this isn’t against the forum rules (I didn’t see anything saying contrary that I could post this link) but here’s a link on EVGA forums where someone showed they got SLI working for 3090s.

I agree this isn’t a required feature, let alone a feature that should have high priority but if it’s possible to implement this feature, that would be another extra utility that eve spectrum would have over everyone else.

Now for the bad news
There are some caveats to the above idea that I would like to mention, they mention there’s issues where the middle of the monitor there is sometimes a vertical tear line because the two GPUs might not be matching up. I know SLI works with Gsync enabled but I don’t know if it can be enabled for this configuration to allow for variable refreshes with no tearing and smooth motion. If gsync/freesync is not possible, it’s not a complete loss because you can essentially try to compensate by having overkill FPS to minimize the tearing while having the lowest input lag possible for backlight strobing (and hopefully no studdering since vsync will be off).

As denoted by blur buster’s page here: Motion Blur Reduction (ULMB, LightBoost, etc) | Blur Busters
Exact quote from the page above
" Optimizing For Reduced Input Lag

Blur Reduction modes by several vendors, may add input lag. There are many tips & tricks by users in Blur Busters Forums to reduce or eliminate “strobe lag” for Blur-Reduction-optimized computer configurations.

Instead of using VSYNC ON which adds input lag, one common alternative is the use of an in-game frame rate cap (such as a Source Engine fps_max setting within CS:GO, Team Fortress, etc). This can allow playing with good motion clarity during VSYNC OFF instead of VSYNC ON, while also eliminating most “Blur Reduction microstutters” issues. And also avoids the input lag of VSYNC ON that can interfere with competitive first-person shooters (FPS games). See HOWTO: Low-Lag VSYNC ON.

An alternative method to reduce microstutters during VSYNC OFF with scrobing, is to use framerates far in excess of refresh rate (such as 300 frames per second or more).

As mentioned in bold there, overkill FPS can be used to make backlight strobing even better by reducing input lag and microstudders! (microstudders are the devil and can ruin a good backlight strobing experience). Needless to say, this feature would be amazing if it can be enabled with backlight strobing at the same time :slight_smile:

I understand that if the above is not possible it’s fine, I don’t expect this would be possible on the eve spectrum but I at least would like to be the first on this forum to at least mention the idea if it can exist :slight_smile:

Needless to say there’s probably less than 0.5% of people left who probably still use SLI for gaming so I don’t expect this feature to get any traction but I do want to bring it up in case eve spectrum does indeed support Picture by Picture (with or without Gsync).

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I can definitely see picture-by-picture mode working. However, it’d be at a fixed refresh rate and not VRR (i.e. different refresh rates per signal).

The problem comes with updating the picture on screen. As far as I’m aware, you can only refresh the full screen at once, not just half the screen. If the left half of the screen is receiving a 97Hz signal, and the right side is receiving a 113Hz signal, at what point do you update? Regardless of what frequency you choose (97Hz, 113Hz or 144Hz) you’ll end up either duplicating frames or skipping frames.

Even ignoring this issue, you’ll almost certainly introduce tearing. Different portions of the screen will be rendering at different times, so you can end up with different parts of the screen showing slightly different views of the image. The same issue happened with SLI when doing top/bottom rendering - you’d often get a horizontal tear line that would move up and down depending on how much of the screen each GPU was handling.

The only way around these issues is if the display driver can guarantee that all GPUs are rendering at the same speed, and that the signal to each display (or, in this case, each half of the display) is at the same frequency. That would make VRR viable and would prevent tearing. However, I’m not sure that Nvidia’s surround view is designed to work that way.

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I personally use Riva statistics tuner to not only cap my frame rate but also get more precise frame pacing. I imagine you could use riva to cap a game to say 97 fps and that would stabilize the frame times for both cards I assume. As for your example of one video signal doing 97 fps and the other 113, the screen should still refresh at the lowest of the two (97 in this example) and I imagine riva could frame pace the stronger card to match the 97 fps so they never exceed the performance of the lowest card. Usually you undervolt the more powerful card of the 2 in order to get the clock speeds to match (that’s what I did) using MSI afterburner.
The other option (and I don’t know if this is viable tbh I haven’t tried it since I don’t have a monitor that supports PBP) is to use riva (RTSS) scanline sync which is lagless Vsync where the tearing line is moved artificially to the top or bottom of the screen away from view.
I know nvidia Mosiac can do this but sadly that’s only available on enterprise cards and not geforce cards :frowning: but say you get a fixed refresh in PBP at say 100 hz, you can in theory still play at 200 fps with no vsync (with RTSS fps cap for frame pacing OR scanline sync) and get less input lag with smooth motion with less studder for backlight strobing. At least in theory, again I can’t test this because I don’t have such a monitor.

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Hi @Liquidshadowfox,

I have brought this feature to the fw team and I’ll let you know their response.

This is an exciting idea and I’m sure they would love to hear about this more.

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Hi @Liquidshadowfox,

Unfortunately, this will not be possible to implement as Picture by Picture is limited to 60hz (4k 60hz) output to the screen.

Just as Jamie stated.

What about on the QHD @ 280 hz model? If not then I suppose it’ll stay a pipe dream

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I’m also interested several days ago when I came across this post :crossed_fingers: :no_mouth:

Hi @Liquidshadowfox & @RocketJumpBlur,

I will find out more about this and will get back to you guys soon :slight_smile:

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Hi @Liquidshadowfox & @RocketJumpBlur,

At the moment we are still looking for the possibility to go beyond 60hz. It will take quite some time, but we will definitely let you guys know as we are exploring the limits.

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That is good. I thank you with all my heart :pray: :pleading_face: :sparkling_heart:

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Any update on this? I understand the QHD 280 hz model got delayed due to some incompatibilities and this could be an opportunity to explore this feature further :slight_smile: if not it’s all good.

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Hi @Liquidshadowfox,

None as of yet, since the team is currently focused on getting the ES07D02 working properly (which is more important!)

Once the ground has settled, then this feature will be something that we can discuss and experiment with. But no promises that it will finally make it to the final product.

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Completely understand about getting the ES07D02 on track. Please keep us updated :slight_smile: We are rooting for this product.

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Hi @Liquidshadowfox & @RocketJumpBlur,

Just so you guys know, the possibility for this feature to push beyond 60Hz has been brought up and is being considered for ES07D02.

I will let you guys know if there are any further updates on this!

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That’s good news :smiling_face:. Thank you very much in advance ^^

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Thank you :slight_smile: Still super excited for this monitor. Just recently bought a gigabyte monitor that is MARGINALLY better with VRR + backlight strobe than my asus but it won’t be anything close to the quality of this monitor if you guys get past the roadblock.

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Is the gigabyte monitor without aorus 1440p 240hz?? If so, could you share your experience or a review on BlurBuster.com for me to read ^^

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No, it’s the cheaper cousin the m27 X that’s 240 hz. It’s got slightly better strobing than the Asus XG27AQM but not by much and I believe ELMB (without Gsync) works better than that monitor but obviously VRR + strobe is preferred. I’ll post a review eventually, still deciding whether to keep this monitor or not to hold me over until eve spectrum arrives.

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