Bobsk8

Stutters at low altitudes in P3D version 3.4

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Been flying P3D for almost 2 years now, and never had any real problems, or OOMs or FPS issues with a 3 year old i5 with a GTX 750 Ti card. I started flying a couple of A2A aircraft then the Q400 then the NGX, and A2A Connie, etc. and most of my flying was probably from 6,000 AGL up to FL370.  About 6 weeks ago I got hooked on flying helicopters, and I have 3 Milviz copters which I love, the 530F, the 407 and the Huey Redux. What I started to noticed was occasional stutters, which I had never noticed before in P3D. I will be flying along about 2,000 Ft AGL, and FPS seem about normal, and all of a sudden I get a sharp drop in FPS for a couple of seconds. It is almost like it catches on something and then back to normal.  I Had run my FPS unlocked or unlimited all this time, and this morning I decided to try an experiment after reading a post by VGBaron, and locked the Frames to 20 and then 22.  This seemed   to eliminate many of the stutters I was getting, although I still had a few on about a 65 mile flight. When I get get one of these stutters, the FPS would momentarily drop to as low as single digits, just for a second, and then go back to 22. I am thinking that this must be happening as the sim is loading a new area of scenery. 

Now my question is, has this been happening all along, and I just didn't notice this when flying at much higher altitudes, and incidentally I have made it a habit of not turning on the FPS counter from almost the day one. In other words, is it much more of a load on the sim, when flying at a low altitudes, because you are closer to the scenery and it is moving faster, compared to what you would see at say 7000 feet or higher and that is why I am now noticing it? Anyway, I was surprised to find that the sim looked pretty good with the FPS locked to 20 and then 22. I was always striving to see higher FPS and it usually varied from around 38-over 50  when unlocked, in most areas.  I think I will keep it at 22 for awhile and see what it feels like.

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Hi Bob - 

Several things - yes, when you fly low and slow the system is trying to provide more detail and is working harder, this will be especially noticeable if you are over or near water. The low frame lock frees up your cpu to put more effort into loading etc rather than trying to get high FPS.

If you can find the right balance for your system, you will be amazed at how smooth P3D is at 20-22fps.

One other thing you might look at, fly default fixed wing low and slow and see if you get the same issue - thinking it might be the helicopter models themselves having an effect - probably not but worth a check.

Other thing to check is if any addon or system process is doing a check or loading something.

 

Vic

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3 hours ago, Bobsk8 said:

Now my question is, has this been happening all along

Yes.  This has been my serious beef with P3D.  When flying GA and is still at 2000 FT, do a turn and you will also see the stutters there too.  Most of tube flier never see this because the gain in altitude is so fast.  If you do turns on approach and at low enough altitude you will also see this.

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2 hours ago, vgbaron said:

One other thing you might look at, fly default fixed wing low and slow and see if you get the same issue - thinking it might be the helicopter models themselves having an effect - probably not but worth a check.

I have never fly helicopter and always see this with all of my fixed wing aircraft.  This will happen especially bad with ORBX scenery. To the point that I now got rid of all ORBX stuffs and GA aircrafts in P3D and only use tube liners.  I tried everything, FF, Affinity mask, my FPS would be around 30-40 with RealAir Legacy V2 and then stutters!

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After giving up on TrackIR that needs 30 fps, after using cashplane.

22 fps is the sweet spot for me just a matter of balancing your setting now Bob.

I did a little guild it's below in my sig if you want to have a read?

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22 FPS locked seems to work very well. 

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I think I have hit on something tights as far as the stutters go.  I have been trying to track down a slight stutter issue with P3D version 3.4, and one of the things I did was to monitor CPU usage in Task manager while flying. I noticed tonight that after about 30 minutes or more of flying, I started to get a bit of stuttering and I now have my FPS locked in P3D to 22, and it is capable with the scenery I am flying over of around 40 fps normally . I also saw the FPS dip a bit under 22 to around 18 or so when I would see the micro stutters. I now looked at the CPU usage with Task manager, and I see that AS 16 is using around 25% or more  at times, and the weather was just some occasional cirrus clouds ( Rex soft clouds) and a steady 13 knot breeze. I felt that this percentage of CPU usage was a toohigh, so while flying, I shut down AS16. I then restarted it, and now the CPU usage is around 2-3 % and the stutters are totally gone and FPS are rock solid at 22. I flew for another 20 minutes, and it remained the same. Any ideas why this could be happening? I have the latest version of AS16  6255. 

 

I also posted this on the AS 16 forum. Seems quite a few others having the same exact problem. https://hifisimtech.com/forums/showthread.php?7863-Stutter-appears-and-increases-over-time-in-P3D-V3-4-18-19475&highlight=high+usage

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It is weird that we now think 22fps is acceptable since it is smooth. In reality, we need much higher than that (35+) at low altitude because when the plane is in a tight turn, the terrain needs to rotate smoothly. 22fps cannot achieve that by simple arithmetic unless you mainly fly in a straight line at low altitude.

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2 hours ago, glider1 said:

It is weird that we now think 22fps is acceptable since it is smooth. In reality, we need much higher than that (35+) at low altitude because when the plane is in a tight turn, the terrain needs to rotate smoothly. 22fps cannot achieve that by simple arithmetic unless you mainly fly in a straight line at low altitude.

Sorry but that is completely incorrect. Smoothness is not a function of FPS. If that were the case, those who say they run at 60fps would never have stutters.

*IF* your sim is smooth at 22, it will be smooth no matter what you are doing, flying straight or turning. There are other factors but FPS and turning are not the major players.

If you tune your system for smooth at 22 in the turns it will be fine straight and level. If you set it up for smooth straight and level it is possible you'll get stutters in the turns.

 

Vic

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+1 Vic

P3D is nothing like FSX at 22 FPS.

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20 hours ago, vgbaron said:

Sorry but that is completely incorrect. Smoothness is not a function of FPS. If that were the case, those who say they run at 60fps would never have stutters.

*IF* your sim is smooth at 22, it will be smooth no matter what you are doing, flying straight or turning. There are other factors but FPS and turning are not the major players.

If you tune your system for smooth at 22 in the turns it will be fine straight and level. If you set it up for smooth straight and level it is possible you'll get stutters in the turns.

 

Vic

When you are in a turn at 22fps, if you look at the terrain beneath you, it renders at a constant rate, but the terrain rendering during rotation is almost at a slide show level. For turns at low altitude to see the terrain passing under you as you would in the real world, we need much higher frames at least 35+.

This is a statement in the obvious. Sorry if you misunderstood me I am not arguing about smoothness. I am arguing about rendition at 22fps. 22fps is acceptable in a straight line and light turns and that is about it.

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1 hour ago, glider1 said:

When you are in a turn at 22fps, if you look at the terrain beneath you, it renders at a constant rate, but the terrain rendering during rotation is almost at a slide show level. For turns at low altitude to see the terrain passing under you as you would in the real world, we need much higher frames at least 35+.

This is a statement in the obvious. Sorry if you misunderstood me I am not arguing about smoothness. I am arguing about rendition at 22fps. 22fps is acceptable in a straight line and light turns and that is about it.

Movies have been made at 24 FPS for decade after decade and many still are, with dog fighting aircraft, race cars etc... Didn't seem to be a problem at all. 

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30 minutes ago, Bobsk8 said:

Movies have been made at 24 FPS for decade after decade and many still are, with dog fighting aircraft, race cars etc... Didn't seem to be a problem at all. 

At 22fps, bank your aircraft at 45 degrees and look out the low facing window at the scenery below. Compare with the same situation at 35fps. Which approximates the visual reality of being in a turn better? That is all I am saying.

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12 minutes ago, glider1 said:

At 22fps, bank your aircraft at 45 degrees and look out the low facing window at the scenery below. Compare with the same situation at 35fps. Which approximates the visual reality of being in a turn better? That is all I am saying.

Been doing that a great deal today in my copter doing pedal turns which are a great deal faster than a fixed wing  aircraft banking. Don't see any issue, and I am locked at 22 FPS. 

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On ‎23‎-‎04‎-‎2017 at 4:06 AM, glider1 said:

It is weird that we now think 22fps is acceptable since it is smooth. In reality, we need much higher than that (35+) at low altitude because when the plane is in a tight turn, the terrain needs to rotate smoothly. 22fps cannot achieve that by simple arithmetic unless you mainly fly in a straight line at low altitude.

Have had similar experience. I have found anything above ~45 fps desirable as that removes the jittery sensation for the most part when panning, but happen to get a taste of it only at cruise. At ~30 find it fairly acceptable not happy with, but below ~25 begins to bother. During airliner landings at large airports since most of the time looking straight ahead with minimal panning, even ~17fps didn't give that noticeable a hindrance.

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