Fsx 4Gb Limit

[Jim Young 2,356]

So what everyone is saying is that I can run 20 32 bit games at the same time on my computer as each game will take up 4GB's of VAS? That's absolutely awesome!

 

In regards to running IE with FSX: Once, when I was starting up FSX, FSX took an abnormal amount of time to start up. It seemed like it was frozen in time. Eventually it started up but every time I tried to do something to get my flight up and running, it would take some time doing so. Frustrated I opened up task manager. Guess what was running, 3 versions of the 32 bit Internet Explorer (I always have 4 tabs opened when I open up Internet Explorer). I had shut down Internet Explorer before I started up FSX but these apps were still running and consuming over 2GB's of memory. I shut them down and FSX opened up and ran great.

 

I really have no problems with your explanations. The point of the argument is that FSX is one process and it can take up 4GB's of VAS (getting up to 4GB's is virtually impossible as remember when we had the /3GB switch and the largeaddressaware switch that give FSX up to 3GB's as other system functions were using the other 1GB?). Running other addons is still part of the FSX process. ASN does not given another 4GB's of VAS and AI is not given another 4GB's and this is what I was trying to point out.

 

So, maybe I shouldn't have stated IE is taking up some of the VAS while FSX is running but I am totally confused as to why IE almost froze up and shutdown FSX when I was running it.

 

Best regards,

[voodoo101 21]

Jim, the problem when you load FSX and was loading Internet explorer is nothing to do with VAS, it is to do with how computers shuffle processing cycles. If you try and start more then any one program at a time then you will have a problem.

 

When you start FSX, your PC takes the program and load it into memory, not VAS memory but normal memory. It does this because the processor calls from the RAM not the hard drive because it is quicker. If you start more then one program then your computer has to load more then one program into memory, this takes longer as it have to share the processes. Once they are loaded into memory then things should be easier.

 

With regards to opening 20 32bit games at a time, then theoretically yes, however even though they get there own virtual space, they still use processor power and memory cycles, so although they will not cause and OOM, they will have affect on each other and they will run slower.

[tttocs 301]

 

 

I really have no problems with your explanations. The point of the argument is that FSX is one process and it can take up 4GB's of VAS (getting up to 4GB's is virtually impossible as remember when we had the /3GB switch and the largeaddressaware switch that give FSX up to 3GB's as other system functions were using the other 1GB?). Running other addons is still part of the FSX process. ASN does not given another 4GB's of VAS and AI is not given another 4GB's and this is what I was trying to point out.

 

The /3GB switch is only relevant on 32 bit versions of Windows where you did, indeed, have a total of 4G to work with for everything, including the OS (and device mapping), as that's all a 32 bit OS can address.  This is not the case in 64-bit Windows with its expanded address space.  Each individual application can address up to 4G of its own address space, and the OS can accomodate that.  However, as you've seen, reducing the number of applications running can certainly impact performance for a variety of reasons, including the fact that as total memory useage exceeds actual physical memory, performance slows as paging to disk must occur.

 

Scott

[mgh 89]

In Microsoft terms, FSX is an application and has it's own VAS.

 

Any .dll called by FSX counts against its maximum allowance of 4gb VAS limit .  However  an .exe file called  by FSX doesn't count against its VAS limit. It  has its own allowance of maximum 4Gb.

 

That's why Microsoft recommends building  SimConnect add-ons as  .exe files rather than as  .dll files, amongst others. A combination of FSX and a single  ,exe add-on can have  8Gb VAS.

[Bert Pieke 7,585]

In Microsoft terms, FSX is an application and has it's own VAS.

 

Any .dll called by FSX counts against its maximum allowance of 4gb VAS limit .  However  an .exe file called  by FSX doesn't count against its VAS limit. It  has its own allowance of maximum 4Gb.

 

That's why Microsoft recommends building  SimConnect add-ons as  .exe files rather than as  .dll files, amongst others. A combination of FSX and a single  ,exe add-on can have  8Gb VAS.

 

Agree - right up to the last line...

 

A combination cannot "have 8GB VAS", but rather 4GB each, as in 2 X 4GB..

 

One of those situations where 2 X 4 is not equal 8  :unsure:

[evaamo 549]

Bert is right, each running process has its own 4GB of VAS. The fact that you call an exe from FSX doesn't give FSX any additional VAS than what it already has (4GB). In any case, the advantage in that scenario is that the add-on will not be consuming FSX's VAS because Windows will grant that exe its own address space.

[mgh 89]

 

 

A combination cannot "have 8GB VAS", but rather 4GB each, as in 2 X 4GB..

 

Yes it can. The first definition of combination is:

 

A joining or merging of different parts or qualities in which the component elements are individually distinct:

 

which is what I wrote. A combination can have 4GB individual distinct elements?

 

http://www.oxforddictionaries.com/definition/english/combination

[goates 576]

So what everyone is saying is that I can run 20 32 bit games at the same time on my computer as each game will take up 4GB's of VAS? That's absolutely awesome!

 

In regards to running IE with FSX: Once, when I was starting up FSX, FSX took an abnormal amount of time to start up. It seemed like it was frozen in time. Eventually it started up but every time I tried to do something to get my flight up and running, it would take some time doing so. Frustrated I opened up task manager. Guess what was running, 3 versions of the 32 bit Internet Explorer (I always have 4 tabs opened when I open up Internet Explorer). I had shut down Internet Explorer before I started up FSX but these apps were still running and consuming over 2GB's of memory. I shut them down and FSX opened up and ran great.

 

I really have no problems with your explanations. The point of the argument is that FSX is one process and it can take up 4GB's of VAS (getting up to 4GB's is virtually impossible as remember when we had the /3GB switch and the largeaddressaware switch that give FSX up to 3GB's as other system functions were using the other 1GB?). Running other addons is still part of the FSX process. ASN does not given another 4GB's of VAS and AI is not given another 4GB's and this is what I was trying to point out.

 

So, maybe I shouldn't have stated IE is taking up some of the VAS while FSX is running but I am totally confused as to why IE almost froze up and shutdown FSX when I was running it.

 

Best regards,

 

Yep, that is exactly what everyone is saying. And it isn't just limited to 32 bit programs. You could run as many programs as you have installed on your machine, both 32 and 64 bit. The big issue when doing that, and possibly what you ran into with FSX and IE, is that there may not be enough physical RAM to accommodate each of the different application virtual address spaces. When space in RAM runs out, the Windows memory manager will try to keep the data for the active program in physical RAM while moving data for the other programs to the page file to make room. When you bring another program to the front, Windows may then have to move things around again. This is part of why switching programs on systems with limited RAM can be slow.

 

I really have no problems with your explanations. The point of the argument is that FSX is one process and it can take up 4GB's of VAS (getting up to 4GB's is virtually impossible as remember when we had the /3GB switch and the largeaddressaware switch that give FSX up to 3GB's as other system functions were using the other 1GB?). 

 

32 bit programs with the large address aware flag set will automatically get a full 4GB of VAS on a 64 bit Windows OS, and don't have to share any of it with the OS. This is because 64 bit Windows has plenty of VAS to accommodate itself on top of the 4GB given to any individual program.

 

Having said all that, yes, the problem with FSX OOMs is that add-ons like aircraft and scenery combined with high settings can increase the sim's VAS usage dramatically. When it gets close to, or tries to exceed, the 4GB limit, bad things will start happening, including the dreaded OOM error.

[SteveW 1,792]

I don't think Gerry is saying that FSX can access 6Gb just because the addon .exe is only using 2Gb. But if the .exe uses 2Gb to do it's thing then it's just as well it wasn't running in FSX space, and as such kind of extends FSX resources that way. Of course an addon.exe comes with a lot more baggage than a .dll, but as others are saying the .exe still has little impact on FSX.

 

With the 64bit OS each 32bit process has a supporting WOW64 process, and threads automatically consume several megabytes overhead. So the 32bit large address aware process on 64bit only gets a little over the 3 1/2 Gb mark In the end.

[Don t moderate me this way 882]

For absolute confusion, let me refer to ASN as an example:

 

ASN is a separate application ("exe"), so it does have its own VAS limit of 4 GB.

 

What ASN also does is, to inject a number of layers with many clouds into FSX, thereby creating objects within FSX, these objects have to be calculated and textured by FSX, thereby increasing the VAS footprint of FSX - despite the fact that ASN has its own 4 GB VAS limit independent of the FSX VAS.

 

Now, how crazy is that?!?  

[SteveW 1,792]

That's a very astute observation Olli. Though I think that's usually considered quite carefully by the weather makers and traffic programs. Hey, a few hundred bytes a second could fill the sim up with aircraft so there's no room in the sky to fly in - thought about that? hehe

[mgh 89]

 

 

I don't think Gerry is saying that FSX can access 6Gb just because the addon .exe is only using 2Gb

 

Exactly. What I actually said was as in your example:

 

A combination of FSX with 4 Gb VAS  and a single .exe add-on with 2Gb VAS can have 6Gb VAS.

[Bert Pieke 7,585]

Sure - I stand by the fact that in this case, 2X4 is not equal 8 and 2+4 is not equal 6..

 

B)

[voodoo101 21]

Oliver, you are not quite right. ASN does not provide any textures so ASN does not actually add to the VAS, well it does with the sound module but that's different. ASN processes the weather to save FSX having to so, it actually reduces FSX VAS memory, it only shows clouds based on the textures you have set in FSX, use the standard textures with exactly the same weather as FSX provides and you will see no difference in VAS. If you use REX at 2048 resolution clouds then you put on a bigger load. The reason that people see more VAS usage with ASN is because you have more realistic representation.

 

Remember that VAS is not just texture usage but it is memory usage, this includes any memory needed for FSX to calculate cloud positions, aircraft positions, turbulence affects on the aircraft and so on. The PMDG 777 is high on VAS for two reasons, one is the 4096 texture sizes for the exterior and the cockpit, two is the amount of systems that have been reproduces. All the things like realistic weather radar and such adds processing needed.

 

There are programs that will help, such as Simstart, that will let you set certain config variables, scenery sets and turn off dll's. If you use AI, get a program called AISIDSTAR, this will take control of AI in the air, this helps release FSX of such a load.

[Don t moderate me this way 882]

Craig, didn't I mention that it's FSX that renders the clouds?  

 

You're stating (correctly) that ASN increases the realism of FSX weather, and FSX provides the textures for it - no matter where those textures come from (native, REX or whatever).

 

BTW, my cloud textures are REX/512 bit, that's a really low VAS impact ... and they look cool!   B)