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Claude Troncy

After one month of P3D

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Bonjour,

 

I am new to P3D, and after one month of navigation between AM, TB, vsync, NI , HT, FPS limiter..., it looks today not too bad. :smile:

 

But there is definitively, with my config, a problem with HT ON.

My config: 4790K OC 4.6Ghz , windows 7 X64, GTX 780, 60 hz monitor.

 

Not too bad with: HT OFF, external limiter (RadeonPro) 30FPS, vsync and TB off, internal FPS limiter illimited and no AM in the cfg file.

 

I choose RadeonPro external limiter as it is the only one which works for me. the others I tried have no effect. Another thing I do not understand as I have a Nvidia card !

 

Concerning HT,

1 With a test flight and no limiters my config can produce 50FPS in turn, with stutters...

2 Limiting the FPS to 30 (preferred external)

    - with HT ON in turn the FPS is not stable and can decrease to 28FPS, with stutters.

    - with HT OFF in turn the FPS is stable (30FPS) and no stutters.

 

So that means that with HT ON something is not logical as my config is able to produce 50FPS. Is it a window problem or a P3D thread synchronisation problem ?

 

Cheers 

Claude

 

 

 

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Bonjour,

 

I am new to P3D, and after one month of navigation between AM, TB, vsync, NI , HT, FPS limiter..., it looks today not too bad. :smile:

 

But there is definitively, with my config, a problem with HT ON.

My config: 4790K OC 4.6Ghz , windows 7 X64, GTX 780, 60 hz monitor.

 

Not too bad with: HT OFF, external limiter (RadeonPro) 30FPS, vsync and TB off, internal FPS limiter illimited and no AM in the cfg file.

 

I choose RadeonPro external limiter as it is the only one which works for me. the others I tried have no effect. Another thing I do not understand as I have a Nvidia card !

 

Concerning HT,

1 With a test flight and no limiters my config can produce 50FPS in turn, with stutters...

2 Limiting the FPS to 30 (preferred external)

    - with HT ON in turn the FPS is not stable and can decrease to 28FPS, with stutters.

    - with HT OFF in turn the FPS is stable (30FPS) and no stutters.

 

So that means that with HT ON something is not logical as my config is able to produce 50FPS. Is it a window problem or a P3D thread synchronisation problem ?

 

Cheers 

Claude

With HT, you need to set a proper AM in the config or you won't get stable fps and smoothness. Try an AM of 116 and shift your addons to cores 1-2 (off the cores that P3D use) using task manager/process lasso or something equivalent.

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I choose RadeonPro external limiter as it is the only one which works for me. the others I tried have no effect. Another thing I do not understand as I have a Nvidia card !

 

RadeonPro might work but using a program that is designed for AMD cards really makes diagnosing any other problem a bit difficult for us here not to mention a feeling of "why bother".

 

gb.

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Your processor looks good for P3d but you might want to consider a GTX 970 level graphics card. PS I have HT off on my system.

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Your processor looks good for P3d but you might want to consider a GTX 970 level graphics card.

 

Well, a GTX-970 is about 10% faster than a GTX-780, so I really wonder why he should consider this...

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Bonjour,

 

Thanks you all for your advices.

 

 

 

With HT, you need to set a proper AM in the config or you won't get stable fps and smoothness.

May be I did not try this one, I just did it and it works OK without the problem of instable 30FPS and micro stutters.

There are a lot of advices about AM, and it is difficult to have an idea.

 

The only thing I know is that AM is an operating system specific, and when an application create a thread using the createthread api there is no way to specify which logical thread is going to be used. The Operating system do the job.

P3D creates about 60 threads which participate to the application. Opus server has about 50. If I understand well all this thread must share 8 logical thread with HT ON, 4 for P3D and 2 for the the addons (core 0)

The way those thread are distributed is the operating system 's job  and sure setting a good AM help P3D as it doesn't know anything. 116 is good (thanks TheBoom). it certainly minimize the switch between major threads. In future P3D devellopment it can change. 

It is only my opinion and may be I am wrong.

 

 

RadeonPro might work but using a program that is designed for AMD cards really makes diagnosing any other problem a bit difficult

I totally agree with you, and I hesitate a lot to try it. But I want to have a stable 30FPS on my 60hz monitor to avoid microstutter, the internal limiter doesn't provide a smooth experience, and the FPS limiter in NI does nothing.

This one works and maintain 30FPS in turn without a problem. It is the only function I use in RadeonPro.

 

 

 

you might want to consider a GTX 970 level graphics card.

 

My gpu usage is about 70%, so I am not sure I need to change.

 

Cheers

Claude

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Claude,

 

I can only speak from my experience which is FPS locked at 60 (and not dropping) for most offline flying,

 

35-40FPS with Orbx SoCal (autogen on high) in downtown San Diego, flying the VRS Superbug, using ASN/SoftClouds.

 

No sure I would see  any advantage to having HT turned on.

 

Good luck with your quest.

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HT on halves the thread switching time across the CPU, improves the use of the cache memories and branch predictions. That's why when we turn off HT we lose a bit of zestiness to the PC. When P3D starts it counts the number of logical processors (LPs) and split's itself into the same number of main thread jobs these occupy every LP found. When we have a four core CPU and turn off HT, and have no AM we get a lovely four cores, or LPs. This is the best way to present a CPU to P3D. There are four LPs unmasked in an AM=0 with four cores since zero=1111 in binary bits to the jobscheduler. Zero is a special case, on a four core = 15. So the sim starts up one thread job per core which is perfect. Turn on HT and we get 8 main thread jobs, two per core. Two Elephants drinking at the same waterhole consume twice as much twice as quickly. So what was MS thinking? Well, we've got a jobscheduler section in the cfg. Good job MS, we can allocate the AM=170=10,10,10,10 or the AM=85=01,01,01,01 and achieve the same result as we do with HT off no AM - except we run the sim on a quicker platform with HT enabled. It's exactly as TheBoom and the other chaps have stated, HT enabled needs care and attention to detail, but there are more options to get around problems running addons and so on.

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Bonjour Steve,

 

All you said makes sens, the switch between thread is logically quicker than between core if the cache is big enough, which is I hope the case for a 4790K

Thanks

Claude

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Two threads on an HT core one per LP share the cache the same as two same threads on a non HT core. All the best Claude.

Steve.

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Bonjour,

 

I am new to P3D, and after one month of navigation between AM, TB, vsync, NI , HT, FPS limiter..., it looks today not too bad. :

 

 

Cheers 

Claude

Don't know where I have been but what do all these terms mean, are the specific to P3D or to do with CPUs and Motherboards. I would love a quick explanation please.

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I would love a quick explanation please.

AM = Affinity mask: used to allocate simulator to particular cores on the processor when you want to run the simulator at the same time as addons and get best performance

TB = ? Texture Bandwidth?

vsync = syncing the graphics output of simulator to the monitor to eliminate tearing

NI = Nvidia Inspector: for doing customised changes to graphics processor settings

HT = Hyper threading: used to optimise CPU performance

FPS limiter = either internally or externally limiting how many video frames the simulator outputs to the graphics processor

 

I could be wrong on some minor details

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My advice: install the sim, change the settings in the sim itself to your liking, lower a few settings if performance isn't too good until it is okay, get used to what you've got and be happy with it. No tweaks, no nothing, pure enjoyment. Everytime I read topics like this I am soooooooo happy to be out of the tweaking business.

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Bonjour,

 

 

TB = ? Texture Bandwidth?

TB was tripple buffering.

 

 

I am soooooooo happy to be out of the tweaking business.

You are a lucky man ! :smile:

My first flight after the P3D installation, was stuttering in turn, in pan, with a lot of shimmering, using a very light aircraft....

As i come from FSXSE, which was for me very fluid, and without stutter, I did not understant why it was so bad even with the cursors at the minimum.

Some people here in the forum, helped me to understand the difference between FSX and P3D. Honestly, the understanding of what is behind each parameter helped me to configure P3D. On the official site of P3D there are also a lot of information in the SDK

 

Every system is different, and unfortunately there is not a quick fix for everyone.

 

Cheers

Claude

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My advice: install the sim, change the settings in the sim itself to your liking, lower a few settings if performance isn't too good until it is okay, get used to what you've got and be happy with it. No tweaks, no nothing, pure enjoyment. Everytime I read topics like this I am soooooooo happy to be out of the tweaking business.

 

But I changed this one line in the cfg and the sim is 478% smoother now! Sure, the FPS is still exactly 27.1 FPS, but it's much smoother! I can tell by the pixels!

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Are you sure about that? I thought it was more like 476%....

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Here's anothe rpiece of advice...stop watching the FPS counter.  It'll drive you mad.  As Jan mentioned here and at another post, the FPS counter isn't exactly a reliable gauge to how your sim performs.  Use your peepers to watch the sim as you fly and see if the smoothness is there.

 

If HT had been on, leave it on and ditch the AM temporarily.  Fly a route and see if smoothness and stability is there.

 

One other thing to consider, to which I didn't see in this thread is about the hard drive performance.  What type of drives are being used?  You can definitely see better performance off a fast SSD, versus a mechanical drive.  Also, what other applications are running on your system while you fly?  Killing background programs before flight helps too.  If you have too much running in the background, your tweaks really won't matter much as your system is trying to play catch up.

 

Sometimes it's the little things that make the difference.

 

-Jim

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But I changed this one line in the cfg and the sim is 478% smoother now! Sure, the FPS is still exactly 27.1 FPS, but it's much smoother! I can tell by the pixels!

 

 

:P

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