As mentioned before, I prefer not to use SP2. Any way to get SP1 to cooperate with the 3GB switch or is this not possible? With the Super MD-80 I am getting occasional OOM's now at the end of flights into dense scenery. There are other workarounds, but I think this might be worth a look a suggested here and in their very helpful forum. Don't want to do Vista 64 until its otherwise necessary.Noel

If the SP1 FSX.exe file is not HiMem enabled, the op system 3G hack wouldn't work anyway. Both must be in place for the magic to happen. Find out if the SP1 FSX.exe is HiMem enabled. If so, it'll take advantage of the op system's 3G hack. If not, ya gotta hack the FSX.exe file. Or just run Vista 64 and SP2. That'd be another answer if your science project just turns out to be too much trouble. Is it otherwise necessary . . . yet?! (Just bite the bullet. You'll thank me later.)

Sam, I found a better option:I used the freeware application called CFF Explorer to allow FSX.exe w/ SP1 to access more than 2GB. So, it works! At least so far it works. I need to do a couple more flights but so far, NO OOMs. Folks on the AWESOME Super MD-80 Professional forum responded with this solution. Very cool! Scary lookin' application though. Looks like you could do some real damage with it!QX9650 w/ Retail HSF|ASUS P5E3 Premium WiFi|4GB Muskin Ascent 7-6-6-18 1T DDR3-1600|EVGA 8800GT|Seagate SATA 2 x 2|Seagate Cheetah 15K.x|XP Pro SP2|Vista 64--maybe never to be installed

Now get this so you can see it coming:http://technet.microsoft.com/en-us/sysinte...s/bb896653.aspxVS is the OOM stuff and WS private is physical memory. This is an intentional 4G OOM with Vista 64. It OOM'd right on schedule with a VS load of > 4G. It's possible, but I really had to work at it. (Notice physical load is also above 3G.) http://forums.avsim.net/user_files/191919.jpgVS will always lead physical ram. FS (therefore) is limited to significantly less than 3G of physical ram usage even with the 3G switches set (cuz VS will get there 1st and shut down the program). - Sans these switches, it's limited to significantly less than 2G. - I often see Above 3G VS with the PMDG airplane. That would OOM even a 3G enabled system. All that fast ram is really put to waste if (only) less than 2Gs were ever used. In this case, a 64bit op system might finally provide a more-than-subjective performance increase. Ram is a terrible thing to waste! See what's going on in real time. Great entertainment.