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styckx

RAM usage

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Was wondering if anyone had an answer to this. Merely observations, not complaining.. Just throwing this out there for discussion because I'm sure there is a rational explanation for this and my brain desires knowledge.

 

I load up Prepar3D with the A36 and my system RAM usage is 2.5GB  used (out of 8GB)  or 30% Physical Usage

 

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I then switch a few different planes.. Switch to a different airport (all default mind you. No addons in play here)

 

I am now up to 6.3GB/73% used

 

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If I just let it sit it frees about 2MB of RAM up a second..  So the million dollar quesiton. Where did 3.8GB of Physical RAM go?  :lol:

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RAMMAP from Sysinternals will show you - not that it matters.

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Found it's all stacking up as Modified Memory.. Right now I have Prepar3D running and 6.6GB of RAM in use.. You'd think I have Windows 8 running in virtualization or something. :lol:  2.6GB of which is modified memory.

 

When I first start Prepar3D

 

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After I change planes a few times or so

 

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According to Technet

 

Modified memory is memory that was allocated by some application and then removed from the application's working set, usually because it hasn't been used for a long time. The fact that most of your memory is in this state means two things:

1. Some app (or multiple apps) allocated a lot of memory, and is not actively using most of it. Often (but not always) this is due to a memory leak in the app.

2. The pagefile is not large enough for the system to move all this unused memory to disk.

 

 

My pagefile was 8.2GB so just for kicks I bumped it up to 12GB and Prepar3D still stacked up the modified memory everytime I changed a plane.

 

Going to reinstall my Nvidia drivers and see what's up, although I doubt it.. No other game, or application I've ever owned stacked RAM like this..  FSX certainly doesn't do it.  I've tried countless times to re-create this in FSX.. Nope.. FSX releases memory constantly... I started out with 4GB in use, changed 4 planes and was at 4.1GB in use..

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Did a complete driver wipe in safe mode.. Reinstalled.. Nope.. Prepar3D still eats RAM every time you change a plane..

 

I have a theory this is directly related to VRAM demand and it mismanaging of it.

 

I just got Prepar3D to total out my system using up 7GB of RAM just merely by changing airplanes a few times. 3.4GB of modified RAM just sitting there doing nothing.

 

ILTL72E.jpg

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As I said it doesn't matter. It's just Windows doing its job.

 

Standby are pages of physical RAM not actively being used and that will be re-used if some other process needs physical RAM for its active pages. Standby pages are essentially caches that retain data in RAM.

 

Modified are similar pages to Standby but they been written to and so need to be written to disk before they can be re-used.

 

It's better to retain even infrequently used data  in RAM “just in case” rather than to pushing it out to disk when the RAM isn’t needed for anything else.

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I actually agree with Gerry. 

 

Not that I find it particularity useful for P3D2/Windows to keep previously loaded aircraft in RAM but, for a training situation maybe it would be.

 

I generally see ~4GB in use total while P3D is running, but I have not tested your specific scenario, reloading aircraft, etc. I'll check it out later after I land.

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I could barely see if it was keeping previously retained plane data but it does it even if you sit and reload the same plane over and over again.. I've noticed this on normal flights too. Even back on Windows 8.. I just was so preoccupied with other things I never sat down to explore it. I've never seen any other application or game ever sit and retain 3.5GB worth of data in RAM it isn't using before.. It really makes no sense to me even in a training situation.. I tried multiple times to do this on FSX in DX9 and DX10 mode and it uses and releases on the fly depending on the aircraft.  Prepar3D 1.4 was the same.. I never saw extremely excessive RAM usage before

 

Save a Flight with the F-22

Close Prepar3D

Start it, observe free RAM

Choose the same livery F-22

Rinse, Repeat and watch your free RAM disappear.. 

 

What is it retaining? 35MB of aircraft textures? I love when RAM is used for a purpose but 3.5GB being used with no conceivable benefit I don't understand.. 

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It really makes no sense to me...

It does make sense. If the RAM isn't needed then why flush it out unnecessarily?

 

As I said, it's better to leave data in RAM just in case rather than having to reload it again from disk.. Nothing has been lost by leaving it there until the RAM's needed by something else.

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I completely get what you're saying.. Just after so many years of monitoring my system (I'm OCD about it) it was just a shock to see a program for the first time send my RAM usage that high.. Only times I come close to seeing it that high was when I have Ubuntu open in virtualization and dedicate 4GB of RAM to it. Photoshop is good for it too if working with multiple hi-res textures.

 

Again.. Just observations.. :)

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High "free" memory use, high vram use...

 

Today I bought my first Titan and the man I bought it from had some kind of game running over 3 screens .

It was a camera view flying over hills , between trees , over detailed grass , over incredible looking water , wonderfull sky with real looking clouds. Magnificent shader effects.

No FSX, no Xplane and no P3D could be compared to this ....

Over 3 screens with incredible sound effects.

 

The vram usage was shown onscreen : 2674 mb.

The fps : 40-70 ...

 

So why is this way better looking , but also more smooth then what we have and at the same time less taxing on the system ?

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High "free" memory use, high vram use...

 

Free memory isn't used by definition so I don't understand your point.

 

 

 

So why is this way better looking , but also more smooth then what we have and at the same time less taxing on the system ?

 

Probably because it's neither P3D nor FSX but a demo intended to show that system to its best advantage.

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Free memory isn't used by definition so I don't understand your point.

 

 

Probably because it's neither P3D nor FSX but a demo intended to show that system to its best advantage.

By free memory I was pointing at the free memory getting smaller when doing nothing...

 

No it wasn' t a demo.

 

Imho those games are built from the ground up using the latest techniics, while P3D is still based on the old FSX code from 2004-2005.

" solve one issue may cause another to appear " ...

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By free memory I was pointing at the free memory getting smaller when doing nothing...

 

If the free memory is reducing then it's been taken for some purpose by Windows, probably for the game .

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No it wasn' t a demo.

 

Give him a ring and ask what game it was! Sounds like a tech demo to me too...

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Give him a ring and ask what game it was! Sounds like a tech demo to me too...

Just asked him.

Unique Valley, à benchmark program.

It was set to the heaviest settings ...

To show what The Titan was capable of.

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Thanks! ^_^ Ah, ok, so a demo after all. Well, that explains why it looked so good! I think it will take a few years before we get benchmark graphics in our flightsim.

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Still I an wondering why P3D van use up to 4.8 Gb of memory on a Titan.

There is no game out there that needs this amount !

 

 

I an curious how P3D will be developed into The future.

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Still I an wondering why P3D van use up to 4.8 Gb of memory on a Titan.

There is no game out there that needs this amount !

 

 

I an curious how P3D will be developed into The future.

 

4.8 GB…? Did you see that on your own Titan?

 

BTW How did things improve with the Titan over the GTX680? A bit better or a lot better? 

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