Let's talk about Render Scaling - Why? Advantages? Disadvantages?

In my case I want something that is more than 2K but I don’t want 4K and I have enough performance room on my GPU to spare so I use 120 render scale. Quality of the image is amazing and the performance is still good enough.

My native resolution is 3440x1440.

In fact rendering a larger resolution is such a good feature to improve visuals that Nvidia has this setting available under the name DSR factor, so that you can make use of it even in games where this option is not available.

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I’d like to set my render scaling slightly below 100 to squeeze a few more frames out. (4k monitor w/ 2080 ti) but since SU5 I get these blue lines in the terrain where tiles meet. It’s terribly noticeable with lower than 100 render scaling but even shows itself at certain angles with 100. This sim is frustrating sometimes.

Indeed, I did.
Thanx to you as well.

Jim-Sim

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To me it looks like there is some LOD change in those images?

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In short … if you are gpu limited don’t and if you are cpu limited do. It really is that easy

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It’s not just about number of pixels on screen, and interpolation. It’s also a temporal thing. This is basically how “pixelshifter” projectors work theese days. Instead of blending pixels, they display them in rapid succession, which adds to the perceived detail and image clarity.

So, with a moving picture you can get a lot more perceived detail than a still image will provide.

Yes, it is a bit strange. If there are any high detail LOD changes based on rendering resolution it’s limited to how the data is handled. I did a test flight with render scale 100 and another with render scale 200 and they both streamed the same amount of data.

The higher render scale did not extend the LOD rings that get retrieved from the server. Both tests streamed 2GB of data from London City to London Heathrow. But it does look the auto-gen scenery is rendered at higher detail. The grass and windows in the auto-gen buildings extend further.

So perhaps auto-gen LOD ranges are affected by render resolution next to terrain and object detail sliders. (Both are set to 200 in those screenshots)

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That is an interesting observation and might be the cause of some people experiencing low apparent LOD range while others don’t, depending on how their render scale is set.

For some time there were many people (not me unfortunately!) finding that the 2D/PC render scale impacted them in VR, and got a big boost in image quality for the same performance by bumping the 2D/PC render scale to 200 whilst leaving the VR scale at 100 or less. Maybe the render scale does impact more things than we expect.

I find a render scale at 120% gives a clearer image. I run at 1080p but if I put this on a large TV it is far too blurry. Increasing the render scale makes it much clearer.

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Although unlikely I suppose 4K could have a different stream to 1080p otherwise the data is constant and local graphic settings only adjust the work allocated to the gpu.

easiest way to see the difference is to test in VR.

you can clearly see how blurry in becomes below 100%, and how crisp it goes above 100

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Have you tried setting to 4k and renderscaling somewhere between 60 - 75%

Even at 2k my PC becomes a slide show, even running at 50% render scaling (1080p).
I’m running a 2070maxq in a thin and light notebook which unfortunately has a terrible cooling solution, so 1080p it is for me unfortunately.

I have a MSI GP75 Leopard with a 10750 + 2070m

Running everything ultra / 200LOD/ 1080p @ 120% scalling with a locked 30fps
Depending of the plane + location, temps are between 85 and 93 celcius with a CPU limited to 3.9ghz

I miss my full PC tower

Well, that’s good to know. I’m getting almost identical performance and temps, 3.9ghz 85-90 degrees with a cooling pad and fully repasted internals. Gigabyte Aero 15 x9 2070.

I miss mine too, but as someone who travels (infrequently with the PC but enough to need it to be portable), I’m limited to notebooks for now. Should have chosen a thicker one though!

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Interesting as at 50% I would expect pretty much the same load on your gpu but load on your cpu on the otherhand I’d expect to increase

So did I. For now I’m blaming the TV, and possibly my 10 year old HDMI cable. Need to do more testing with better hardware.

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The render scaling acts as a sort of forced FSAA, but one of the prime benefits comes into play when any sort of distortion is applied to the image. It’s mildly visible with ‘lens distortion’ turned on, as this feature expands the center of the frame and contracts the outer portion, to improve the experience when using very wide monitors. By rendering at a higher initial resolution, the image degradation due to the stretching and compression is reduced. This is even more pronounced with the more extreme distortion applied for VR use. With render scaling at 100%, small text is hard to read in VR, while at render scaling 200%, it is much clearer.

Nah it’s the same source data that gets streamed. You don’t get higher quality textures or higher detail PG data at higher resolution.

I did several tests and while it varies a little bit, it’s so small it’s most likely due to some stuff getting missed (flying faster than streaming can keep up)

For render resolution 100 (1080p render) I got 1.92 GiB and 2.04 GiB streamed in two tests.
For render resolution 200 (4K render) I got 1.99 GiB streamed.

That’s with pre-cache slider at Ultra, it you lower that it does stream in a little less (out of view data) During the test I left the camera pointing forward so no extra reloading.

Pre-cache ultra 2.04 / 1.99 / 1.92 GiB
Pre-cache high 1.98 GiB
Pre-cache medium 1.72 GiB
Pre-cache low 1.73 GiB

Looks like for pre-cache there’s only 2 settings when it comes to streaming (low/med vs high/ultra) and I guess a fine tune step where it comes to rendering.

Yet autogen scenery does seem to be affected by render resolution. Maybe not only the detail on the buildings and grass, but also the draw distance how far trees and auto-gen buildings extend. Next time I’ll make some comparisons while over a PG city and somewhere where the tree line and/or autogen building range is clearly visible.