nyc01

I did try it and it isn't any better than 60Hz/60 fps, it was actually worse on the one display I tried it on. 30Hz/30 fps also works for me as long as you double check the v-sync option in Prepar3D. Have you ever seen X-Plane 10 run using this method? If you want to see the ultimate in fluid game play from flight sim try running FS2004 or aerofly FS running at a consistent 60 fps with v-sync enabled.

If you can't force a 29Hz or 30Hz refresh rate then using 59Hz is pretty much a waste of time. If you can maintain a consistent 60 fps and your display runs at 60Hz the v-sync option in Prepar3D will be your best option.

You can force lower refresh rates on a display in the Nvidia control panel and the AMD Catalyst Control Center. I posted some information about it in response #94 on page 4 of this thread - http://forum.avsim.net/topic/434948-p3dv21-stutter-or-no-stutter/page-4 and page 5 of this thread - http://www.prepar3d.com/forum-5/?mingleforumaction=viewtopic&t=5533.4

If you set the frame rate to unlimited and you are able to get over 60+ fps, when v-sync enabled it will keep the frame rate from going higher than the refresh rate (60Hz/60 fps). It's a test to see if v-sync is really enabled or not. I just got done with a fresh install of Windows 7/SP1 64 and just like I've seen with Windows 8.1 when I exit out of the sim with v-sync enabled, it's not working when restarting Prepar3D. The frame rates are showing over 120 fps when I start a new flight, going back into the graphic settings and then exiting re-enables v-sync and the frame rate display doesn't go above 60 fps. At this point I suspect many users who claim they are seeing stuttering aren't even running the sim with v-sync enabled which because of frame rate fluctuations will produce stuttering.

I should have been more specific, you'll have to use settings (or an airport/scenery area) that will allow for a frame rate higher than the refresh rate of your display, which I assume is 60Hz so you'll need to obtain frame rates higher than 60 fps.

I will Rob as soon as I get it installed but I was also hoping you could give us your results with the scenario I mentioned, did you check the frame rate when you think v-sync is enabled?

Set you frame rate to unlimited with the v-sync option enabled and then exit out of the sim and start it back up again and take a look at what your frame rate is. I'm asking because when running on Windows 8.1 anyway v-sync is'nt staying enabled (which I mentioned earlier). I was able to reproduce this issue on two different systems and I'm in the process of trying it on a fresh install of Windows 7.

Or stutters related to the frame rate not consistently matching the refresh rate with v-sync enabled. The same stutters that are present with FSX and X-Plane (and a dozen other sim/games I run) when the frame rate doesn't match the fresh rate of the display. Is v-sync enabled? If yes how are you confirming that is enabled and working?

The frame rate will drop if v-sync is enabled and stuttering will occur as the refresh rate/frame rate is divided. It's no different then what we've seen in FSX or X-Plane with the ½ refresh rate option. If the frame rate can consistently match the refresh rate of display with v-sync enabled the stuttering is eliminated. That's the whole reason behind the ½ refresh rate option and Nvidia's G-Sync to begin with. If you can't maintain 60 fps with a particular game but you can at least maintain 30 fps the option allows you to divide the refresh rate and run it at 30Hz. The problem is the ½ refresh rate option isn't working with Prepar3d v2 so unless you force 30Hz on the display like I described earlier in this thread you are going to see stuttering unless you turn the settings down low and run at 60 fps. If it's not v-sync related then why was able to eliminate then by forcing 30Hz on my display with v-sync enabled on two different systems? How come the stuttering is eliminated when the settings in Prepar3D are turned down to maintain 60 fps with v-sync enabled? I would call it a refresh rate/frame rate mismatch issue not a v-sync issue which is present with every sim/game out there if you can't get the frame rate to match the refresh rate of the display when v-sync is enabled. Here's a better one that adds triple buffering to the mix - http://www.anandtech.com/show/2794

Exactly, the refresh rate is 60Hz and and you are running the sim at 34 fps so how is going to be possible to stutter free performance with those settings? There's no way currently to force the refresh rate to 30Hz so your display is still running at 60Hz. With the settings turned all the way down the frame rates were in the 300-400 fps range on my system. At those settings with the frame rate locked at 60 fps with v-sync/triple buffering enabled the stutters were gone because the frame was able to consistently match the refresh rate.

If the display runs natively at 60Hz how are you getting it to run at ½ of the refresh rate/30Hz?

Have you tested it yet with the frame rate locked to the refresh rate of the display with v-sync enabled?

I bought the SteveFX - DX10 Scenery Fixer when it was released last year and was amazed at how fluid 30 fps could be in FSX. The big difference between Prepar3D v2.1 and FSX with the DX10 fix is that the ½ refresh rate option actually works with FSX/DX10 it doesn't with Prepar3D. The stuttering is now pretty much centered around not being able to lock the refresh rate to the frame rate with v-sync enabled, with v2.0 the stuttering also was related to the lack of optimization. Forcing the displays refresh rate to match the frame rate for me has pretty much completely eliminated the stuttering in v2.1.

In the Adjust desktop size and position under Display in the Nvidia control panel you can try the Override the scaling mode set by games and programs option. Set the drop down option under Perform scaling on: to GPU. The Customize option should now be available to you under Change resolution.

You should be able to create a custom resolution in the Nvidia control panel and set it to 30Hz. I installed the 334.89's on a fresh OS and didn't see any difference from the 334.67's I had installed before. I haven't had any problems with them so far with Prepar3D or X-plane 10. Like I mentioned earlier forcing the ½ refresh rate option in the Nvidia control panel or by way of Nvidia Inspector isn't doing anything yet with the 334.67 or 334.89 drivers. As far as the 144Hz refresh rate goes unless you can run the sim/game at a consistent 144 fps I don't see how it's going to help anything. With G-Sync you will see an improvement because the refresh rate is continuously variable with the frame rate. I guess if that were true, why would stuttering be high on the list of LM's bug fixes right after 2.0 was released? They even admitted they had stuttering issues with 2.0. I have seen a significant drop in stuttering with 2.1 compared to 2.0 and from what I can see so far all of the stuttering issues now are related to the frame rate not matching the refresh rate with v-sync enabled (no different then what you would see in any other sim/game).

If you can consistently maintain 30+ fps try going into the Nvidia control panel and set your refresh rate to 30Hz along with v-sync/triple buffering in Prepar3D and see if the micro stuttering is gone.

Yes I did test it with Terrain shadows on.

Something new I tried tonight brings me back to one of my original suggestions in a discussion with LM when Prepar3D v2.0 was first released last year. I decided to try the same exact way I used to run FSX before Nvidia added the ½ refresh option, running the display at 30Hz. I went into the Nvidia control panel and set the resolution to 1920x1080@30Hz and then fired up Prepar3D with the frame lock set at 30 fps and v-sync/triple buffering enabled. As I suspected when the frame rate is locked at the refresh rate of the display (as long as you can maintain 30 fps) there's no stuttering at all. You have to turn eye candy settings down considerably in Prepar3D even with the highest end hardware in order to consistently maintain 60 fps which is obviously why I'm still seeing some stuttering with the frame rate set at unlimited and v-sync enabled. With those settings every time I drop below 60 fps some stuttering will occur as v-sync divides the refresh rate. Unless Lockheed Martin makes resolution options in the menu available with a 30Hz refresh rate (which I have seen in other sims/games) or Nvidia's ½ refresh rate option finally works with Prepar3D I don't see any other way to completely get rid of the stuttering (unless you are using a G-Sync display).

Thanks for the info, I'd be curious to see if the adaptive v-sync is even working. I can check again but from what I can see Nvidia Inspector and Nvidia's control panel still isn't forcing any settings on Prepar3d. There was a comment made by LM in their forum that said they recommended the unlimited frame rate setting along with v-sync/triple buffering enabled in order to see anything that resembles fluid performance. After playing around with the frame rate lock I have to agree with them. I'd like to know the magic specs also, lol. That's another subject that hasn't been brought up with the claims of stutter free performance. Stutter free compared to what? I have to seriously question some of the claims I've seen here and over in LM's site on how smooth and fluid Prepar3D v2.0/2.1 really is. Many of the Prepar3D users from what I can gather from comments being made are oblivious to the stuttering and probably have never seen a sim/game even run at a consistent 60 fps with v-sync enabled. Let's face it, FSX was certainly never any benchmark for fluid game play, lol. Smooth, fluid performance to me would be something on par with what I've personally seen from say Outerra running at 60+ fps along with v-sync/triple buffering enabled. Some of the combat flight sims out there or racing sims (iRacing or Asseto Corsa comes to mind). Even X-Plane 10 running at 60 fps v-sync/triple buffering is pretty good as far as fluid game-play is concerned.

That's why I asked, if the display is running at 144Hz with v-sync enabled and the frame rate is only 50-70 fps how would you see anything but stuttering? Are you using a HDTV capable of a 144Hz refresh rate? The reason why I'm asking is because I have seen some HDTV's that will only do 60Hz when the signal is coming from a PC.

You are running on displays with a 144Hz refresh rate and are able to maintain 144 fps? If so with what settings? Are they HDTV's or are they something else? As far as I've seen so far since v2.1 was released, NI still doesn't have any control over Prepar3D's exe. The ½ refresh rate setting still doesn't seem to be doing anything with Prepar3d v2.1.

Yes I've seen the frame rate spikes with v-sync enabled but with the issue I'm describing the frame rates never even hover around 60 fps, they stay in the 70 – 80 fps range until I go back into the settings and check the v-sync option again. Are you running on Windows 7, now you've got me wondering if it's a Windows 8/v-sync issue? I might just go ahead and see if I can reproduce the issue on my i7/AMD 290X setup.

If I have v-sync enabled and then completely close out of the sim and then start it again the frame rates are above 60 fps, which shows that v-sync is no longer enabled.

So far I haven't been able to reproduce this issue with the Nvidia 334.67's or the 334.89's, but this was only with the default scenery and FTX AU SP4.

It stays checked it just doesn't stay enabled. With v-sync enabled obviously the frame rate shouldn't go above the refresh rate of the display (in my case it's 60Hz/60 fps). When I close out of the sim and then start it again the frame rates are 80+ fps, v-sync is again disabled. If v-sync isn't enabled and the frame rate limiter is set to unlimited just like with any other game you will see some stuttering no matter how high the frame rate is. I installed them last night and didn't see any difference from the 334.67's. Next up I might just try a fresh install of Windows 7/SP1 64 to see if there's any difference compared to Windows 8.1 Pro.