Somebody stop me... (Gaming PC Build Thread)

[Rare White Ape]

Alright some notes about running a super ultra curved, super ultra wide monitor. Please indulge me as I get into the weeds of technicality a little bit.

It's a 49" Samsung G9 Neo, 5120x1440, 240 Hz, HDR, variable refresh etc etc. Top of the tree. Previously I used my 55" 4K TV but ran it in 1080p mode so that I could get 120 Hz out of it.

It's now mounted above my pedals on the VESA mount which came with my racing rig, whereas before the screen was on a TV stand almost twice as far away. The screen has the same physical width as my TV but half the height. Using iRacing's built-in FOV calculator I went from 53 to 84 degrees, so I get a significant increase. I do lose about 20% of screen height though, so 16:9 video is smaller but 2.39:1 movies are bigger provided they fill the screen.

Good bits:

Response time and input lag is nearly zero. This is a very minor difference to my TV which had one of the lowest input lag scores of any TV when I bought it in 2018; 7 ms in game mode. Now it's purportedly 1 ms, and I'd be hard pressed to see the difference.

Very wide and even display of colour and brightness. Makes games feel like they're on a huge theatre screen, which I had only experienced in VR before. Landing a small plane on a big runway in MSFS makes you feel small! The centre of screen is also up at my eye level now, which helps a lot.

Multitasking. I can have a billion windows open side-by-side. Samsung even has a neat piece of software called Easy Setting Box where you can customise the preferred size of your windows with a drag-and-drop interface, which might even be useful for people with normal screens, so check it out. Another good one is picture-by-picture, where the monitor can display two full-screen 16:9 images from two of the three inputs. You can mix-and match between HDMI or Display Port, pick which input uses the left or right, or even overlay an image on the corner on top of a full 32:9 main screen.

Best feature is VRR provided by G-Sync. I now have absolutely zero tearing, and uneven frame rates might still look choppy but they're displayed much better. It's even palatable when the scenery around MSFS's Manhattan pushes your GPU into 15-20 fps territory, so long as you don't look sideways. A nice calm forward viewpoint is best here. Anything above 45 FPS looks like silky smooth 60, and above 60 is just butter.

Bad bits:

Nothing caused by the monitor, but here is where things go deep with my own findings, which may not be correct, but here goes...

Almost no games truly support this monitor. It's meant to be the best, and in a hobby where people always want the best it's surprising that there is nothing said about this. The core of the problem is that all games assume you have a flat screen, and display 3D images accordingly. When you take this flat perspective and then curve it around you, the far portions of the screen become distorted. Add in a lack of lens correction and it is even worse. Let me explain with a really shitty graphic:



Look at games in this way: your eye is the camera, and the screen is a window to the 3D world. Objects are presented to you as if the screen is your window for looking at a 3D environment. The outermost edges of the screen represent your FOV, and if you want things displayed realistically you will want the calculated FOV to be correct. For sim racing this is very important, but for other games it might be a personal preference or a 'nice to have' feature.

Now consider what it means when the screen is curved around you. In the graphic, the place where the lines intersect is where the objects should be rendered on the screen. If the screen is curved, these locations will change. As you can see the lines converge onto different locations of the curved screen compared to the flat screen. But since most games display only a flat image, you will get a warped perspective because you're essentially looking at the image from the wrong angle.

As mentioned earlier, Halo Infinite looks terrible. Great game, but distracting warping. Here are some examples. The first image is using the default Halo setting of 78 degrees FOV. Look at the tower right in the centre of the image.



Here's the same scene, same settings, but I pan to the left and the same tower is now at the far right edge of the image. It now takes up roughly twice the horizontal screen area of the first image, and is quite a bit taller. The base is the same level because it is near the centre of the screen, where distortion is much lower.



Here are comparison shots of Halo in the default 78-degree FOV, as well as the calculated 'correct' (for my setup) FOV of 84, and the minimum of 65 degrees. Yes, I made jifs for you!



I even have video of what it looks like in motion, both using Halo's default FOV.





It's so badly exaggerated when flying the aerial vehicles that I don't know how they would let this go. A partial fix for this is to use lens correction. Here's what it looks like in MSFS.



As you can see they increase the size of objects in the middle of the screen so that the objects nearer the edges are in a more correct perspective. This is a stop-gap measure as it probably only accounts for flat screens. And even then, I think what Halo looks like is far too much for lens correction to sort out.

[Rare White Ape]

How does iRacing fix this? There are two things it does. Firstly, it has the option to allow the game to render the screen as three separate images with zero bezel width. I know Assetto Corsa Competitzione has a similar option, and other sims may do this too. iRacing has an excellent built-in calculation tool that does all the wok for you; just plug in the usual distance and width numbers and the radius of the curve and it will split the screen, easy as that.



I tried ACC's triple screen settings menu and it'll do the same thing, but you have to enter it all manually. I did the sums: screen width 397mm, angle of side screens 22.9 degrees. You will have to provide your own distance measurement, which is definitely a DIYC process. Here's another really shitty graphic to help out:



Here is what iRacing looks like in both corrected and uncorrected perspectives. You might see that the magnitude of the change is much higher than the example shown from MSFS. ACC looks very much the same. Perfect:





However....

Look closely at the corrected viewport of the bottom image.



It might be hard to notice at first, but the top of the structure near the top edge of the image has two noticeably warped sections on it. This is also present in ACC. Nearer the horizontal centre of the image it's not noticeable, but at the top edge it's very clear, and quite distracting while driving because it moves along like a wave going through the grandstand. Thankfully at the bottom the view is mostly taken up by the interior of the vehicle which doesn't move a lot otherwise it would be noticeable there too. Here's some arrows to help point it out:



There is another artefact that comes from the multi-projection setup. See if you can spot it.



There is a noticeable gap in the motion blur effect, also present in ACC. Again, helpful arrows for your pleasure.



What I believe is happening here is:
1. For the 'waves' at the intersection of the projections, the game is projecting three flat screens, so you get the warping again, but reduced intensity and in the middle of the screen.
2. For the motion blur, things like this are calculated in screen space using data from the previous frame, and because this is the edge between viewports there might not be enough information to blur what is displayed on this part of the image. You are essentially looking at a clean portion of the frame not obscured by motion blur.

I believe these two problems are unavoidable for now. To fix the first one you would have to render the game using a unique camera for every pixel. To fix the second, it might mean rendering a small overlap, which would take up unnecessary processing power or introduce other perspective issues. I live with them in order to appreciate the fix they have provided.

Finally, what else has iRacing done that puts them above all other games with this solution? The secret is in the extra check-box in the monitor setup screen: Enable SMP/MVP. Nobody else does this.

What is SMP/MVP?

It's a technique that GPUs use to share rendering tasks across multiple view ports. For Nvidia cards it's called Simultaneous Multi Projection. For AMD cards it's called Multi View Projection. Things like wireframes, textures, shadows, and other effects are calculated once and shared to each rendering view instead of having to be done multiple times. It was originally developed by Nvidia and introduced in the 10-series Pascal cards as a way to solve the problem of needing to buy multiple GPUs to render multiple view ports at full quality, and iRacing supported it way back then.

Since then it has only seen adoption in VR games, because it can be used to pre-warp each eye image before it is projected through the VR headset lenses and into your eyeballs. SMP can run 16 projections at once! For VR, each eye is split into four quadrants and warped, as well as having the rendering shared for each eye.

And no games apart from iRacing support it for non-VR screen use, as far as I can tell.

[Rare White Ape]

Thanks for coming to my Ted Talk.

[Yobbo NZ]

All I know is, I can't play my Xbox on a flat screen/TV anymore after using a curved monitor.

[Yw-slayer]

Man, some major first world problems going on here.

*Goes to buy a 1TB SSD for his work notebook*

[Alan P]

I have a friend who has one of these and he plays most normal games in 3440x1440p and puts up with black borders at the extreme edges. As you've said very few games support such a wide resolution without any issues of one sort or another.

[21Kid]

Thanks for coming to my Ted Talk.

LOL

I didn't even realize they still made curved screens. Your setup does look pretty sweet though.

I don't know if there'd be any way to correct teh issue you're having. That seems like it would take a lot of computational redirection to fix.

[Blerpa]

I have a friend who has one of these and he plays most normal games in 3440x1440p and puts up with black borders at the extreme edges. As you've said very few games support such a wide resolution without any issues of one sort or another.

3440x1440p is the standard 21:9 resolution for QHD, I have it as well.
Aside from Fallout 4 and Elden Ring, plus few indie games, the whole PC videogame industry market supports that resolution with no trouble, so your friend is doing something wrong.

Also, most of the 21:9 monitors are curved for practicity reasons, the only 21:9 flat screens are mostly LG office monitors. 32:9 follows the same guise.
Meanwhile curved 16:9 monitors are quite useless to this day.

[Rare White Ape]

I didn't even realize they still made curved screens. Your setup does look pretty sweet though.

Thanks! And yeah curved screens are out of style for TVs but still quite common for monitors.

I don't know if there'd be any way to correct teh issue you're having. That seems like it would take a lot of computational redirection to fix.

From what I’ve been reading, adding additional virtual cameras and simultaneous processing is really easy at the game engine level.

[21Kid]

From what I’ve been reading, adding additional virtual cameras and simultaneous processing is really easy at the game engine level.

Makes sense... like how iRacing does it in your earlier post.