How Much Memory Does FSX Really Need?

[flyguy737]

Ok so I mean let's face it FSX is very resource hungry yes we have all discovered that and the Specs that Microsoft supplied originally certainly don't make FSX really effective. All of us have upgraded over and over and with more and more great addons for FSX becoming reality like ORBX etc I am starting to wonder just how much Memory is really enough?

Ok take Captain Sim's 767 which I recently purchased. It runs ok under win7 but still is very slow at loading textures etc. Now if I run the same aircraft with win XP I get out of memory errors. I lower my scenery settings but still can't maintain it running under win xp. Now even other addons like Heathrow and other airports that are hungry for memory can cause this error even with default aircraft.

Ok now under win xp my system says 3.25 gig ram and under win7 it shows the whole 6 gig. So you are all saying well stay with win7 but that is not what I am getting at.

What I am trying to figure out is why I get out of memory errors at all? Is it RAM or is it something else that cause's this? Is it the type of RAM being used? Is it GPU Memory that cause's the OOM errors?

Are there settings in FSX.CFG that should be changed or can be changed to reduce or stop this error occuring? I have tried some tweaks in the past but not sure which is doing what. So can someone shed the light in layman's terms and tell me what tweaks if any I should be using and at what settings?

Should I just delete the cfg and let FSX rebuild it but I don't think that will stop the OOM errors. Would Vista Home Premium which I also have be better to install over XP? I use the pro version of XP SP3.

The more I understand why FSX behaves the way it does the better I can understand the needs for future upgrades.

Colin

[Conchulio]

Hey mate,

i wouldn't say that i am qualified enough in technical aspects but one thing i can say for sure. DON'T go back to Vista under any circumstances. XP is still the way to go or Win7 altthough i don't see ANY improvements concerning performance within FSX when chaning from XP to Win7 at all but i see a big drop in performance when using Vista.

I recently had the chance to use both Win7 and Vista from 2 different HDs and to be honest, no change for me from my original Win XP SP3.

Yes, Vista and Win7 both use all of my 4 gigs of RAM but who cares when FSX NEVER used more than approx. 2.2-2.6 gigs at all with 4096 cloud textures, PMDG MD-11F at YMML V1.5 on a typicall cloudy day in melbourne?

I think it's a myth that the more RAM you have, the better fsx goes with textures in generall. Empirically from my point of view, it is really unnecessary to have more than 4gigs at all for FSX. I will stick with XP SP3 until i am really forced to switch over to Win7 but that will take some time. No need to switch now as concerning FSX i see no fundamental hard fact that changes anything.

Concerning your OOM issue. Well, i also had that problem but nowadays i rarely had them, except the very first time i used YBBN when everything was checked... it killed my comp 

I think it is a good start to let FSX rebuild your fsx.cfg but unfortunately there are so many reasons why an OOM issue appears it's hard to say why 

But, nonetheless, one thing for sure; Don't got back to Vista, that's like going one step back in evolution 

Conchi

[flyguy737]

good info Conchi but still need to find out why the OOM's are occuring with addons.

[Ian Routley]

Colin ... How have you got your 6Gig configured?

Mix and matching DIMMs is likely to be unstable under load.

If you have 2G x 2 sticks and 1G x 2 sticks then this is likely to be your problem.

  If you have 2G x 3 sticks, then this is likely to be worse.

OOM errors are rare in FSX under Win 7 64bit if your system is properly configured.

In short, FSX places demands on a computer, but that just means it needs a well thought-out system ... not that it has "specific" requirements.

The reason many users have 6G is because Socket 1366 boards need 3 sticks to run DDR3 in triple channel mode, and the logical configuration is 2Gig x 3 = 6Gig (one for each channel)

So ... stay calm.  Configure your system properly, and it will likely be stable.  Serial upgrading should be done with care

Pull out the unmatched DIMMs ... and go flying.

[flyguy737]

Hi mate I should have said I don't get the OOM's under win 7 all the RAM is matched and is fine under win7. I get the OOM's under XP and that's what I am trying to figure out. Even when I had only the 4gig I still had OOM's under heavy loads.

[TheAviator]

Is this what the HIGHMEMFIX=1 tweak is for?

[flyguy737]

well that's something I wonder too?

[Ian Routley]

.....  I don't get the OOM's under win 7 ......  I get the OOM's under XP.......

then you have answered your own question.

Use Win 7.

[flyguy737]

well see that's true I could stick with win7 however I am trrying to find out why it happens with XP. See one thing I like about XP is that I can stretch the image across 2 monitors until I get the TH2GO and this gives a very nice view and I can't do that under win7.

[peterhayes]

FlyGuy

What you are seeing here has little to do with physical ram installed.  It is to do with virtual address space or virtual memory.  Win XP 32 bit didn't handle this well and OOMs occurred regularly as the VAS is easily exceeded especially if you are using a modern video card.  Vista and Windows 7 address memory very differently but the the 32-bit variations will always be prone to OOM's.  In a 64-bit OS, Win XP, Vista or Win 7 you should not run out of VAS if your rig is properly configured, and you do not overload the system with all the bells and whistles fully right.  Even in a 64-bit sysytem running a 32-bit program there is only 4GB of VAS available and that can be exceeded especially in FSX.  For example, the problem is compounded by today's huge GPU RAM video cards which can eat into the VAS making less available for FSX, and couple that with resource memory add-ons such as a complex plane and/or scenery and you may again exceed the VAS available and get OOM's.  It is important to separate Virtual memory from Physical RAM, because even under a 64-bit OS running a 32-bit program, and having as much as 192GB of the fastest RAM available installed you could still run out of memory.  

Note  In a 32-bit OS there is only 2 GB of VAS available for FSX (NO SP2) and Up to 3 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE (FSX SP2). If you "exceed" physical RAM you use the paging file if you run out of VAS - BSOD!

Regards

PeterH

[John Lovell]

Colin ... How have you got your 6Gig configured?

Mix and matching DIMMs is likely to be unstable under load.

If you have 2G x 2 sticks and 1G x 2 sticks then this is likely to be your problem.

  If you have 2G x 3 sticks, then this is likely to be worse.

OOM errors are rare in FSX under Win 7 64bit if your system is properly configured.

In short, FSX places demands on a computer, but that just means it needs a well thought-out system ... not that it has "specific" requirements.

The reason many users have 6G is because Socket 1366 boards need 3 sticks to run DDR3 in triple channel mode, and the logical configuration is 2Gig x 3 = 6Gig (one for each channel)

So ... stay calm.  Configure your system properly, and it will likely be stable.  Serial upgrading should be done with care

Pull out the unmatched DIMMs ... and go flying.

I had 9gigs of mis matched sticks 2 gig x3 and 1 gig x3 and was getting all sorts of problems.

Recently removed the 1gig sticks and now have 6 gigs  (2gigsx 3)

Remarkable improvement, my computer is running more in harmony

[flyguy737]

thanks guys and Peter for all that info. hmmm very strange indeed. ok so tell me this if you can why can't I stretch the image in win7? I was told you can't but not explained why after all if your running 2 monitors and you can extend the desktop, why can't you stretch it across them ?