First my computer specs.

i78700k OC 4.8 ghz.

Nvidia RTX 2080

32 gb Corsair Vengeance RAM @ 3200mhz

Samsung 970 EVO Plus SSD.

Dell monitor with GSync 2560x1440 @ 144hz

I fly the FS Labs A319/320 exclusively for Prepar3d 4.5 It recommends using MSAA for anti aliasing which i’ve always done. Today, for fun I tried 8x SSAA.  For some unknown reason it actually runs the sim smoother in all situations.  I tried lower SSAA settings and there was no difference in smoothness or frames whether it was 2x or 8x SSAA.

 

I understand the different Anti Aliasing techniques, and SSAA should tax the system more.   Others have reported bad stuttering.  The opposite is the case for me.  Anyone have insight into why this is?

 

Thanks.

Guthrie Zuehlke

 

 

 

Make sure to test it with heavy clouds+precip and at night with dynamic lighting...those are the scenarios that will clobber performance with aggressive SSAA settings.

Could be the heavy AA load is reducing the amount of fluctuation in frame rates--that's what causes stuttering.  A lower rate with less variation (especially with G-Sync) may actually appear smoother.

Regards

Thanks for the suggestion!  I loaded up at LaGuardia in a major thunderstorm at night with dynamic lighting on, and flew an approach.  30+ frames both inside and outside the cockpit.  I know this sounds crazy but it's smooth.

Guthrie Zuehlke

Do you run with the vsync box unchecked in P3D, along with "Unlimited" fps set in P3D?

Yes I do. I turned on the dome lights using FSlabs Spotlight.  This instantly cut frames in half with 8x SSAA.  Went back to 8x MSAA got maybe 4 frames back.  Went down to 4x SSAA, and frame rate was the same as 8x MSAA...Around 25-35 fps.

The weird thing is that the Frame Rates are showing 25-35 fps inside the cockpit with dome lights on during T/O yet it appears smooth.  Flight over New York at night in a thunderstorm with dynamic lighting on, dome lights on...smooth.

 

Guthrie Zuehlke

Edited August 29, 20196 yr by usmc3073

Hello Guthrie,

Seems like the RTX 2080 do like heavy load.
I understand you, I know it sounds crazy but I get the same feeling as yours.
MSAA or SSAA doesn't make any difference in fps, even in the middle of heavy storms and clouds like today flying from LIRF with the FS Labs Bus.
What does make a huge difference on my rig is the clouds texture resolution which stays @512.

 

Agreed, SSAA looks so much better on my rig (same as OP except I am still with the GTX 1080Ti) for not a huge FPS hit.  I run 4xSSAA all the time now.  Looking great.  I also run the clouds at 512 as you David, and they look just fine (ASCA).  

 

I always ignore the FSL greeting which wants to turn it back down to MSAA.  

Do you get 30FPS even with your dynamic landing lights illuminating the scene?

On my 1080ti I can run SSAA8x but as soon as the landing lights are on, FPS halved 

@8x SSAA it cuts the frames but it is still smooth.  So stuttering is non existent.  Because of all the addons I run I upgraded my RAM to 32 mb and that did seem to speed up my system some.  Before I upgraded, I had 16gb.  I monitored my RAM usage and it was using 80% or more pretty consistently.  Once I doubled it things got smoother.  I think it was bottle necking my CPU.  I know a lot of addons will soak up RAM.  The most important thing, however is the speed of the RAM.  

Edited August 29, 20196 yr by usmc3073

I've been running my RTX 2080Ti at 8xSSAA for several months with no performance issues, but I did have apparent AA problems with some PBR materials.

Recently, I used Nvidia Inspector to add 4xSGSS and the results are stunning. No more PBR shimmering. FPS above 30 pretty much  everywhere all the time, even at night. 

3 hours ago, usmc3073 said:

Yes I do.   (run no vsync and unlimited frames)

Ok, in that case... maybe the above...

5 hours ago, w6kd said:

Could be the heavy AA load is reducing the amount of fluctuation in frame rates--that's what causes stuttering.  A lower rate with less variation (especially with G-Sync) may actually appear smoother.

Regards

...unlimited (no vsync) tends to be less smooth BUT maybe what Bob mentions above -- loading it down for less variation -- is making it smoother.  Just a wild guess though.   It's interesting.

3 minutes ago, MDFlier said:

I've been running my RTX 2080Ti at 8xSSAA for several months with no performance issues, but I did have apparent AA problems with some PBR materials.

Recently, I used Nvidia Inspector to add 4xSGSS and the results are stunning. No more PBR shimmering. FPS above 30 pretty much  everywhere all the time, even at night. 

In the past I've had stability issues with SGSS.  I may need to try, with the latest nVidia driver.

2 hours ago, Mace said:

In the past I've had stability issues with SGSS.  I may need to try, with the latest nVidia driver.

In general, the RTX 2080 series seem to be able to handle 8xSSAA with ease. The caveat being that some of the nVidia drivers that I have used in the past have not performed as well as others. There were one or two a while ago that had atrocious performance using 8xSSAA. I'm not on the latest driver. I installed the new "low latency" driver (I think it was 436.02), but I was seeing artifacts on the control panel when panning the view. It looked like in the movies whenever a character is on drugs or gets hit really hard and they show the world through their eyes and everything has motion blur... I rolled back to 431.06 which works great. I usually try to keep them current, so I just downloaded 436.15 to see if they've fixed the blur.

Guthrie - Try using nVidia Inspector to set Antialiasing Transparency Supersampling to 4x Sparse Grid Supersampling. It really cleans up shimmering on the PBR stuff, and also helps with other things like the runway textures at FSDT KCLT, which look really nice with it active.

 

Edited August 29, 20196 yr by MDFlier

I wonder if my 1080Ti can handle 2x or 4x SSSA? I run an i9 9900k and 64gb of physical RAM. I am on a 4k 50in TV so that 1080Ti might struggle too much. I'm on 4x MSAA now with FXAA on to smooth things out somewhat.

2 hours ago, MDFlier said:

In general, the RTX 2080 series seem to be able to handle 8xSSAA with ease. The caveat being that some of the nVidia drivers that I have used in the past have not performed as well as others. There were one or two a while ago that had atrocious performance using 8xSSAA. I'm not on the latest driver. I installed the new "low latency" driver (I think it was 436.02), but I was seeing artifacts on the control panel when panning the view. It looked like in the movies whenever a character is on drugs or gets hit really hard and they show the world through their eyes and everything has motion blur... I rolled back to 431.06 which works great. I usually try to keep them current, so I just downloaded 436.15 to see if they've fixed the blur.

Guthrie - Try using nVidia Inspector to set Antialiasing Transparency Supersampling to 4x Sparse Grid Supersampling. It really cleans up shimmering on the PBR stuff, and also helps with other things like the runway textures at FSDT KCLT, which look really nice with it active.

 

Thanks for the advice i'll do it and report back

 

Guthrie Zuehlke

Edited August 30, 20196 yr by usmc3073