I said it was quite possible...infact I clearly quoted an Article that said it was.. so not this time dazz. So please read Phi'ls blog and find out what isn't. So with 2.8 Gigs how's the frame rates and the stability?After all you have 0 cpu usage there.

You are using RAM and address space in the same sentence several times over..."3 GB of RAM out of a 4 GB address space" is, no disrespect, like comparing apples and oranges Better would be: "3 GB Partition out of a 4 GB address space"RAM is physical chips that you stick in your computer. MS calls this "Physical storage"Address space is a mapping construct that is internal to the OS.http://msdn.microsoft.com/en-us/library/aa366912%28v=vs.85%29.aspx

Words often have more than one meaning. While "address space" to you is an OS construct, to me it is 2**32 = 4 GBy. (This is likely also the more often used meaning.) So I stant by my original sentence that FSX can use 3 GBy of RAM out of a total address space of 4 GBy.

Well i guess you could always show us your running FSX.exe thats 2gig+...? Phil clearly states DirectX was never compatible with 3gig hence why it never was worked into any version of FSX. I think you'd be hardpressed to find ANY DX9 game working over 2gigs.. but obviously this works so you will post the pics right?

I never run FSX in DX9. Do mean the DirectX 2 GBy limit also applies to DX10?

I said it was quite possible...infact I clearly quoted an Article that said it was.. so not this time dazz. So please read Phi'ls blog and find out what isn't. So with 2.8 Gigs how's the frame rates and the stability?After all you have 0 cpu usage there.

0 CPU useage likely because FSX is stopped when he switched away to another app: Task Manager! :-)Cheers,- jahman.

Yesterday I also got an RAM usage of neraly 2,75 GB, so it´s over 2 GB and in DX 9 mode. So you see, that DX 9 can adress more than 2 GB.

Yeah I think you can get up to 6 gigs easy.... 3 cpus, 3 processes 3x2gigs =6. Does FSX work underthose conditions no... probably why the CPU is 0 locked up waiting for memory.

Back on topic, the OP is asking whether or not upgrading to 8GBy of RAM will make a difference in FSX, the answer is no, not a significant change.

Thats somehow sad, but I think I´ll stick with my 4GB, looks that´s more than enough.Another question: Would it make sense to change the producer of my RAM? I´m actually running some Vdata RAM and I´m not knowing if there is any difference beteween my actually and an Corsair factured one.

Words often have more than one meaning. While "address space" to you is an OS construct, to me it is 2**32 = 4 GBy. (This is likely also the more often used meaning.) So I stant by my original sentence that FSX can use 3 GBy of RAM out of a total address space of 4 GBy.Cheers,- jahman.

You are ducking the issue. You are explaining your use of the term "address space".My issue is with your use of the term "RAM".Somehow your explanation makes it sound as if FSX uses a certain amount of physical memory (RAM).And that you can change how much RAM FSX uses by the /3GB flag.The /3GB flag gives FSX a bigger share of the address space at the cost of the system share.But this is equally true on a system with 2 GB of RAM or 8 GB of RAM.RAM usage is dictated by the OS, not by FSX.

Yes I believe FSX uses a stack and a heap... no idea where the 2^32 fits in unless you do pointer manipulations.. but even then it's controlled by the OS.

You are ducking the issue. You are explaining your use of the term "address space".My issue is with your use of the term "RAM".Somehow your explanation makes it sound as if FSX uses a certain amount of physical memory (RAM).And that you can change how much RAM FSX uses by the /3GB flag.RAM usage is dictated by the OS, not by FSX.

I'm not ducking the issue, I'm just trying to understand where we are not understanding each other. RAM is a short way of saying "memory used by a program". So in my original phrase when I said FSX could use 3 GBy of RAM out of a 4 GBy address space, that would mean the program could use up to 3 GBy of 32-bit virtual memory from an absolute maximum of 4 Gby addressable by the compiled machine code of that program due to the use of 4-byte memory pointers. Hope this clears it up.

The /3GB flag gives FSX a bigger share of the address space at the cost of the system share.But this is equally true on a system with 2 GB of RAM or 8 GB of RAM.

This is correct. But if the system sports a 64-bit OS, then the size of the system share that needs to be part of the 32-bit compatibility box will be smaller as most other system services not related to FSX can continue running native in 64-bit address space and use memory way beyond 4 GBy. I still have no idea of what the minimum size of this compatibiity box is, but since some simmers are reporting FSX memory use just over 2.5 GBy, then the size of the OS 32-bit footprint would appear to be 4 GBy - 2.5 GBy = 1.5 GBy.Cheers,- jahman.

I love it when the non programmers tells use how things work....

I'm not ducking the issue, I'm just trying to understand where we are not understanding each other. RAM is a short way of saying "memory used by a program". - jahman.

OK, that is where we are not understanding each other. RAM = memory used, is sloppy at best, in this case misleading..The OP wanted to know if he should increase his installed RAM beyond 4 GB.Your response has to do with "memory"=address space. OK, but not related to the original question.RAM is "physical memory used", not address space used

I love it when the non programmers tells use how things work....

Bet you never wrote a virtual memory OS in assembly language, and the emulator to run it on a mainframe! Not sure if that makes me a programmer though... :-)

OK, that is where we are not understanding each other. RAM = memory used, is sloppy at best, in this case misleading..The OP wanted to know if he should increase his installed RAM beyond 4 GB.Your response has to do with "memory"=address space. OK, but not related to the original question.RAM is "physical memory used", not address space used

In the context of the OP's question, it makes no difference whether RAM means physical memory or address space: FSX can't use more than "about" 3 GBy of either.Cheers,- jahman.

In the context of the OP's question, it makes no difference whether RAM means physical memory or address space: FSX can't use more than "about" 3 GBy of either.Cheers,- jahman.

Happy to see that you've found something we can agree on!

I wish programmers would tell us why FSX was programmed so inefficiently...

Isn't that the Bill Gates business model?scott s..

I wish programmers would tell us why FSX was programmed so inefficiently...

We all want FS to be coded efficiently, to run aircraft add-ons from two versions back, to be updated frequently and to be cheap. Something's gotta give :-)Consider silicon is cheaper than programmimg, so "inefficient code" is not necessarily a bad idea. Inefficiency is actually built into just about every piece of sotware we use: Just about all code today is written in inefficient C, even less efficient C++ or way less efficient C# (.NET): If all the code were written in assembly language, it would run about 3x faster than code written in C on the same machine! The speed difference would be even greater for C++ and C#. But the cost to develop and maintain assembly language code is prohibitive, so to make software cheaper we have to spend more on hardware.Cheers,- jahman.