Sign in to follow this  
blahhhblahhh

CPU load

Recommended Posts

Hello,
I'm trying to tweak the p3d config in order to gain some additional fps and use more the cpu. Currently I put everything to high/ultra, the gpu (hd7970) loads up to 90% but I'm not able to use more than 40% of my cpu (i5 2500k @4.5k).
I've tried to set the affinity mask to 14 according to the documentation, but only one core is used, the three others look at the first one working...
On a busy scenery (FSdreamteam or mega airport) with the carenado hawker I got between 40 and 60 fps with some drops at 30. But it seems to be instable, always cycling between 40-60...
Have I miss something?
In any others recent games like GTA 5, the gpu and cpu are full loaded and I like it :)
Thanks for your help.

Share this post


Link to post
Help AVSIM continue to serve you!
Please donate today!

try this

[JobScheduler]

AffinityMask =0

 


[Main]

FIBER_FRAME_TIME_FRACTION=0.005

 

Share this post


Link to post

 P3D doesn't really compare to GTA -  Mostly P3D is still only a single threaded app so the only thing the other cores are getting used for is scenery loading and a few other things. 

 

Bottom line is that you will see 1 core getting 100% used and the others only coming to life for scenery loading etc.

Don't try to use the windows task manager CPU usage as a performance indicator as it averages all cores together which in the case of P3D is useless..

 

You are getting unstable framerates because you are using unlimited FPS. Try setting a limit of 35 or so. Yes you will get a slightly lower FPS but it will not stutter and should run smooth.

 

I recommend to stay away from .cfg tweaks as most don't amount to a hill of beans and you will be back next week looking for another tweak to fix the problems the first one caused.

Share this post


Link to post

I concur with Slayer.  I set my FPS at 40 and hope for 30.  The human eye can only process 24 FPS so why the need for high framerates?

Share this post


Link to post

Waoo thank you guys!

AffinityMask + FIBER_FRAME_TIME_FRACTION + fps limiter = this is just perfect. You are right, limited fps seem to be more smooth!

 

 

The human eye can only process 24 FPS

 

Fortunately it's wrong. 24 fps is acceptable but not fluid. It's why movies recording are now up to 48 fps (60 for the next Avatar).

60 fps is more comfortable.

Share this post


Link to post

 

Effectively, thanks for sharing.
 
Finally I still have some fps drops after applying these tweaks.
I have decreased the scenery complexity and autogen to normal and 
I installed Prio then set high priority to the p3d process and set the affinity mask thru this tools (cores 1, 2 and 3 ; core 0 is free).
Right now I've 40 to 60 fps (limited to 40) without any drops with the carenado hawker (pilot view,  60 to 80 on external views) on a busy photo scenery. Core 0 seems to be used by pro atc, asnext and ezca.
It rocks!

my cpu now loads to 70-80% each core is used.

Share this post


Link to post

 

 


Mostly P3D is still only a single threaded app so the only thing the other cores are getting used for is scenery loading and a few other things. 

 

That is somewhat misleading, as scenery loading is pretty CPU intensive. Core 0 manages the entire P3d app, so to speak, so it generally is the bottleneck in terms of performance. ASN uses any core available to it, but you can prevent it from using core zero by setting its own affinity mask.

Share this post


Link to post

Are you sure that scenario are managed thru the main p3d thread?

Cause now i've 3 cores used at the same time (first one @100%, the 2 others @60-90% depending the flight phase)


and it's so beautiful :)

Share this post


Link to post

That is somewhat misleading, as scenery loading is pretty CPU intensive. Core 0 manages the entire P3d app, so to speak, so it generally is the bottleneck in terms of performance. ASN uses any core available to it, but you can prevent it from using core zero by setting its own affinity mask.

 

I didn't mean it to be misleading, just trying to simplify for a new user of P3D is all. But yes, as you and I know it goes way deeper than that as Iv'e seen you post in several of these topics as well. Baby steps before throwing in .cfg edits and tweaks.  :P

Are you sure that scenario are managed thru the main p3d thread?

Cause now i've 3 cores used at the same time (first one @100%, the 2 others @60-90% depending the flight phase)

and it's so beautiful :)

 

Yes the main thread spawns the loading processes on the other cores to load scenery in the the background to keep the main thread from bogging down/ causing stutters. Consider that P3D has to encompass a whole world whereas GTA is a small area. Once you cross into a new area not already cached in your computers memory will cause the new scenery to start loading. This is where the load on the other cores starts to happen. The other cores will also be used by several other addons but since your new I was assuming you don't own any of those yet?

Share this post


Link to post

I've tried to set the affinity mask to 14 according to the documentation, but only one core is used, the three others look at the first one working...

I installed Prio...and set the affinity mask thru this tools (cores 1, 2 and 3 ; core 0 is free)

Not to put too fine a point on it, but no one mentioned that on your 4 core, "(cores 1, 2 and 3 ; core 0 is free)", would actually equate to an AM=14=(1110) So you should have been fine with that. At least in the end you got your three main cores going and your addons are on the unused core, that's the main thing. Others note that a CPU with hyperthreading enabled would not want an AM=14, but that's another story.

 

 

You are right, limited fps seem to be more smooth!

You might like to know that the "limiter" is not just an fps limit, but also this prepares look-ahead frames. Although they do eat into the maximum fps slightly, they are consumed when the scene changes, and rebuilt during easier-going scenes. So you've got some frames in hand when the scene complexity demands too much time to be able to prepare the next frame. When you're panning the view, the consistent time between frames is much easier on the eye than high fps. The sim is actually designed from the ground up to work that way, unlimited is mainly used for performance and setup testing, at least that's all I use it for.

 

With unlimited setting, panning rotation rate constantly alters to the tune of the image complexity. It's easy to see the panning rotation speed up and slow down as the complexity of the scene changes. This effects the handling of the plane since when making a turn, we are effectively panning the view, and with unlimited setting, the turning rate alters just as panning does. Maybe not an issue with tubes and AP set on all day, but try a glider and the flow of the turn is as notchy as panning the view. Unless we exceed the refresh rate of the monitor where the fps evens out.

 

Another consideration with Unlimited is that any addons that work from a frame event basis, may be forced to run at unnecessarily high speeds.

 

Finally, content of the next frame is worked out based on the time between frames. With limited fps we have a consistent time between frames that the physics, positional data, and so on, are calculated against. With the unlimited setting, the next frame hardly ever concurs with the real time it was produced for. Even so, most calculations come out fine, but there is evidence to suggest that position, and even fuel used may be less reliable with unlimited, but not by much.

Share this post


Link to post

Thanks a lot for all these explanation!

Some people said that it might be better to use an external fps limiter. Is it true?
Other people recommends to set a max fps in p3d (eg 30) and use also an external limiter (set to 40 for exeample). What is the benefit?

Share this post


Link to post

Thanks a lot for all these explanation!

Some people said that it might be better to use an external fps limiter. Is it true?

Other people recommends to set a max fps in p3d (eg 30) and use also an external limiter (set to 40 for example). What is the benefit?

Not much. With P3D stick with fixed fps below that which can be maintained throughout the flight. I use 20fixed. If I had a more powerful PC I would turn up the details and stick with 20. If I had a really powerful PC, maybe twice as fast, I might increase to 30 fixed.

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this