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hefewe1zen

FSX never using more than 2GB RAM

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I'm mostly aware of memory restrictions of FSX and that it cannot utilize more than 2GB of RAM (usage 70% overall). However, it's only using 1900MB of memory according to task manager and never going above that. CPU is an old and cheap AMD, cores are continually operating around 100%. Could it be that CPU is a bottleneck which results in limited RAM use?

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How much RAM do you have total?  While FSX can use up to 4GB, it has to share RAM with other applications that are also running.  

 

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1 hour ago, hefewe1zen said:

I'm mostly aware of memory restrictions of FSX and that it cannot utilize more than 2GB of RAM (usage 70% overall). However, it's only using 1900MB of memory according to task manager and never going above that. CPU is an old and cheap AMD, cores are continually operating around 100%. Could it be that CPU is a bottleneck which results in limited RAM use?

FSX can use an unlimited amount of RAM but usually will not use more than 8GB's.  To be safe, it is recommended you have at least 16GB's of RAM for any computer system.  It appears you might be confusing virtual address space (VAS) with RAM.  FSX, on a 64 bit operating system, can use up to 4GB's of VAS as it is a 32 bit application.  If you have a 32 bit operating system, then FSX can only use up to 3GB's of RAM and that is with a /3GB switch. 

If you have a 64 bit application like P3DV4 or XP11, you have an unlimited amount of VAS (well up to approx 8 terabytes).

More information can be found on page 36, AVSIM CTD Guide or in the Intro Guide in the PMDG Documentation around page 21.

Best regards,

Jim

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Just now, hefewe1zen said:

I'm mostly aware of memory restrictions of FSX and that it cannot utilize more than 2GB of RAM (usage 70% overall). However, it's only using 1900MB of memory according to task manager and never going above that. CPU is an old and cheap AMD, cores are continually operating around 100%. Could it be that CPU is a bottleneck which results in limited RAM use?

This is normal.. A faster CPU will not use more RAM..

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On 22 December 2018 at 3:57 PM, Jim Young said:

FSX can use an unlimited amount of RAM but usually will not use more than 8GB's. 

That's not true. FSX is a 32 bit program and, therefore, can only ever use a maximum of 4GB of memory. That’s due to the 32bit address space: 2^32 = 4,294,967,296 bytes. If you run it in a 64 bit OS and have more than 4GB of RAM then all of the 4GB will be allocated to it, but no more. Any other 32 bit applications running concurrently will also be allocated up to 4 GB depending on the maximum amount of RAM available. 

Edited by vortex681

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If it will not use more than 2GB perhaps your OS is 32 bit

and no one has added the 3 GB switch.

Edited by nolonger

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2 hours ago, vortex681 said:

can only ever use a maximum of 4GB of memory

This is true but you are talking about virtual address space which is not memory.  Microsoft allocates up to 4GB's of VAS on a 64 bit system and up to 3GB on a 32 bit system that has the /3GB switch.  I was talking about RAM, those memory modules that sit on your MB.  More details are on page 36, AVSIM CTD Guide or around page 21, PMDG Intro Guides.

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There is no difference in this context.

Virtual Address Space allocates RAM to a program so that program sees nothing of any other programs that may be running

and they see nothing of it.

4GB of VAS means that up to 4GB of memory as required has been reserved for that program and is therefore directly related to 4GB of RAM.

FSX cannot use more than 4GB of RAM because the operating system cannot allocate it any more than 4GB of Virtual Address Space.

The most likely answer to this question

" However, it's only using 1900MB of memory according to task manager and never going above that."

is that the operating system is 32 bit.

The distinction is relevant where the question, as asked many thousands of times, is

"I have the most powerful computer with 32 GB of installed RAM and yet FSX runs out of memory. How can this be?"

This is not the question asked here.

 

Edited by nolonger

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37 minutes ago, nolonger said:

Virtual Address Space allocates RAM to a program so that program sees nothing of any other programs that may be running

and they see nothing of it.

I think you need to do a lot of research before you post.  This is clearly out of your league.

 

38 minutes ago, nolonger said:

The distinction is relevant where the question, as asked many thousands of times, is

"I have the most powerful computer with 32 GB of installed RAM and yet FSX runs out of memory. How can this be?"

The error message is correct.  When you run out of memory, you are actually running out of VAS.  Tabs from PMDG explains it the best in the PMDG Intro guides.  I think he states something like Microsoft should have never have called this error as an out of memory error as it is not memory.  It is virtual address space or space for applications to run.  When the application uses up all of the VAS, it will crash.  It should have been entitled, ran out of virtual address space.

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Why is the OP's PC not using more than "1900MB of memory"?

 

 

Edited by nolonger

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18 minutes ago, nolonger said:

 

Why is the OP's PC not using more than "1900MB of memory"?

 

 

I am not sure there is a problem here.. why try to find something wrong when all sounds normal? :unsure:

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13 minutes ago, nolonger said:

Thanks.

Why is the OP's PC not using more than "1900MB of memory"?

Yes, you asked this before... what would you expect FSX memory usage to be?

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I am only wondering what the answer might be to the original question, given the presence in this topic

of such expertise. So far, no one seems to have addressed it.

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The OPs question actually was why FSX was not using more than 1900MB of memory.

And given that my FSX install routinely shows less than 1000MB of memory being used in Task Manager, I would suggest that the answer is:

"This is normal, take an Aspirin, get a good night's sleep, and all will be well in the morning."  :wink:

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Sorry, that may have come across as unkind..

Lets try again..

The OPs question actually was:

"Could it be that CPU is a bottleneck which results in limited RAM use?"

And my answer to this question was:

"This is normal.. A faster CPU will not use more RAM."

And that is what I still believe.  :wink:

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On 26 December 2018 at 1:26 PM, Jim Young said:

This is true but you are talking about virtual address space which is not memory.  Microsoft allocates up to 4GB's of VAS on a 64 bit system and up to 3GB on a 32 bit system that has the /3GB switch.  I was talking about RAM, those memory modules that sit on your MB.  More details are on page 36, AVSIM CTD Guide or around page 21, PMDG Intro Guides.

Yes, but in its simplest form, VAS is just effectively a portion of physical RAM that the OS allocates to a process or program. You said that FSX can use an unlimited amount of RAM but it doesn't matter how much RAM you have, FSX will only ever "see" (use) a maximum of 4GB of it. It doesn't get VAS and RAM.

Edited by vortex681

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36 minutes ago, vortex681 said:

Yes, but in its simplest form, VAS is just effectively a portion of physical RAM that the OS allocates to a process or program. You said that FSX can use an unlimited amount of RAM but it doesn't matter how much RAM you have, FSX will only ever "see" (use) a maximum of 4GB of it. It doesn't get VAS and RAM.

Totally agree and why I also have P3DV4 which is a 64-bit application that gives me up to 8 terabytes of VAS.

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47 minutes ago, vortex681 said:

Yes, but in its simplest form, VAS is just effectively a portion of physical RAM that the OS allocates to a process or program. You said that FSX can use an unlimited amount of RAM but it doesn't matter how much RAM you have, FSX will only ever "see" (use) a maximum of 4GB of it. It doesn't get VAS and RAM.

And in a slightly less simple form, VAS is actually a superset of RAM that the OS allocates..

Remember, you can have 2 GB of RAM installed and still run FSX with 3 or 4 GB address space.

So RAM can be bigger or smaller than VAS, the OS does the mapping..

Edited by Bert Pieke

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10 hours ago, Bert Pieke said:

So RAM can be bigger or smaller than VAS, the OS does the mapping..

Yes, but it can never map/allocate more than 4GB to a 32 bit process.

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5 hours ago, vortex681 said:

Yes, but it can never map/allocate more than 4GB to a 32 bit process.

Agreed!

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For the OP: CPU makes no difference to RAM allocation.  FSX is a 32 bit program and cannot use more than 4 GB of RAM.  Add-on aircraft, scenery, and utilities, - and increasing the aircraft and surface traffic - will bump up the RAM used by the software.  Get a VAS monitor (like the one in FSUIPC - I believe it is available in the free version) and you will get a better idea of how FSX utilizes the 4 GB of RAM that is available for its use.

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