Guys, those of you, who have used that switch enabling the use of 4GB RAM under WinXP, do you think it is good for running FSX? Can you share your experience and impressions you have accumulated by now?Thanks.

I tried on my old box to do this and this completely trashed my audio and video drivers, and my AV solution would hang. I think that I had too many drivers relying on the upper address space and not behaving properly. I said the heck with it and got Vista 64 with 4Gb of memory and lived virtually happily ever after with no more OOMs.Etienne

What switch are you referring to?

If you mean the /3GB /userva=2560 switch in boot.ini that enables FSX to use more than 2 GB of virtual memory, I can only say that it cured the OOM errors I was getting with no bad side effects.Note that you do not need to have more than 2 GB actual RAM memory for this to work !Q6600 - 2 GB PC800 RAM - 8600 GTS 256 MB - WinXP Pro - FSX Accel

I have four 4GB of memory, and use the switch Bert provided above. In addition, there is a program that can alter the FSX.exe to also utilize more than 2GB.I'm at work right now, but can provide the program title later, or, go to the 'hardware' forum and do a search for 4GB, and you will probably find a fairly complete post/thread on the software you need, and additional switch info.With these 'tweaks' activated, my XP machine can 'see' about 3.17GB of RAM, and it did help out FSX on my system. In addition, with 4GB of RAM, I am 'ready to go' should I decide to move to Vista.

I believe that as of SP2, FSX is already >2GB aware, so you do not need any further program.

>If you mean the /3GB /userva=2560 switch in boot.ini that>enables FSX to use more than 2 GB of virtual memory, I can>only say that it cured the OOM errors I was getting with no>bad side effects.>>Note that you do not need to have more than 2 GB actual RAM>memory for this to work !>>Q6600 - 2 GB PC800 RAM - 8600 GTS 256 MB - WinXP Pro - FSX>AccelThanks, guys. I'm not sure about this part: /userva=2560 - what is it for? I did /3GB only. I was told on another forum that FSX SP2 was >2GB memory aware. But I'm very interested to find that utility and try to apply it to FS9.exe as well. I got physical 4 sticks of RAM. I'm also attracted by Vista 64bit SP1 on the 2nd boot disk, maybe later.Thank you again.

>I have four 4GB of memory, and use the switch Bert provided>above. In addition, there is a program that can alter the>FSX.exe to also utilize more than 2GB.>>I'm at work right now, but can provide the program title>later.Guys, can you please recall the name of that utility? Anything else do I need to try it on FSX SP1 and or FS9.exe?Also, are there any (BAD) side-effects of having 1Gb video memory onboard of of my GT8800 card? I understood that the TOTAL memory WinXP 32 bit could take on was 4Gb. 2Gb went to programs (like MSFS), the rest was used by the system and devices. Now, having 1Gb of memory on the video board instead of 512Mb, what happens?Thanks.

Take a look at this thread, it is the info I used to set-up everything:http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchandhttp://forums.avsim.net/dcboard.php?az=sho...ing_type=search

Dirk,Here's the thread with the relevant information: http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchRegards,Jim Karn

Note that this was written prior to SP2.No need for the fsx.exe modification, it is included in SP2.

Not really an issue Bert, as if you open the FSX.exe after installing FSX SP2, it will already show it is set-up for use with over 3GB. I know, as I checked my install after SP2.As they say, 'no harm, no foul' ;)

Thanks, guys! Tweaking Vista 64 SP1.

Hi Dirk98,no need to tweak anything if you use Vista 64.If you have SP2 the EXE is already tweaked and Vista 64 already capable of using more than 2 GB.So there is nothing to do here.

Thanks, Markus. There are many things I'd like to tweak/adjust in Vista. I can say I'm almost happy with WV64 SP1, and tweaked as it is now on my PC, it finally looks almost like WinXP, all stripped down. I'm impressed with it and FSX SP2. I knew that FSX SP2 was 2GB+ aware, thanks for posting.Dirk.