Hitching and Stuttering = Max FPS set too high

[Mr_Blastman]

So I inadvertently discovered what was causing my huge stuttering and framerate hitches.  I have not flown DCS in 10 months because I have traveling.  When I jumped into the sim I was concerned about the stalls/pops in framerate.

 

I tried turning off background process, changing graphics settings, etc., deleted shader caches, but nothing worked, until...

 

I saw that in DCS Graphics Settings the "Max FPS" was defaulted to 180.

 

Well, that shouldn't be an issue, right?  WRONG

 

I lowered Max FPS to 60 and poof, the hitching went away.  Buttery smooth DCS followed.

 

Is this a bug?  If not, this should be stickied to help others.

Edited September 21, 2024 by Mr_Blastman

[razo+r]

With hitches do you mean screen tearing? Because that happens if the software doesn't run on the same FPS as the Hz on your Monitor, in which case you should enable V/G/Free-Sync.

[Mr_Blastman]

34 minutes ago, razo+r said:

With hitches do you mean screen tearing? Because that happens if the software doesn't run on the same FPS as the Hz on your Monitor, in which case you should enable V/G/Free-Sync.

Definitely _not_ screen tearing.  Imagine panning the mouse around your parked aircraft in 3rd person view, and suddenly seeing the screen pause for a moment, then jerk free and your view has been teleported.

[Moezilla]

You are right that if you ask the CPU and GPU to work flat-out to deliver as many frames as possible there can be moments where the CPU gets a spike in demand that causes the GPU to wait, and then the GPU load drops, and FPS follows. It is better in general to cap the FPS at a level where your CPU has a small amount of headroom to absorb the smaller load spikes. There's nothing much that can be done if the mission spawns 10 moving columns right under you or a huge cruise missile strike lands.

But something to check since you mentioned you haven't played DCS for 10 months, there is an issue with high-polling rate setting in mouse software. Until the issue is fixed the polling rate should be set to 500Hz or lower. The symptom of the issue is, as you described, looking around causing hitching.