HiFirst time I tried longer flight with MD11, and first question:1.How much fuel do I need for flight EDDF-LDZA? I loaded with 80t, and after TO I check on PROG page and EFOB=7.2t still I get Insufficient fuel message on MCDU.Second, I hope that I will manage to end my flight because I had for first time real OOM message with fs9 shutdown.Now I trying again with AI turned off. Strange, OOM happened somewhere near Iceland and I don't have any scenery installed on that area.ThanksEdin H.fs9, XP 32 bit, 4Gb RAM, C2D, ATI2900XT 1Gb

Your problem with OOMs is that your running a 32bit operating system. Just do a search for OOM and you'll find some fixes that MIGHT help you with that problem.

Your problem with OOMs is that your running a 32bit operating system. Just do a search for OOM and you'll find some fixes that MIGHT help you with that problem.

ThanksI know everything about OOM, but I didn't have it till now.The problem is with longer flights also with MD11 and B747.I will go for 64bit OS, because I didn't have a luck with 3GB sw. Which one is better XP 64bit or Win7 64 bit regarding compatibility issuesEdin H.

A 64bit OS might fix the memory issues but might give you a whole new world of different problems, e. g. driver and compatibility issues.I'd recommend looking at your current 32bit setup first and exhaust all available options before thinking about going Vista or Windows 7.I do not recommend XP 64bit. You'll most definitely have driver problems with this one.I run a 4 GB machine with Windows XP SP3 32bit, FSX SP2, UT scenery (USA/CAN/Europe) and REX 2.0, and the PMDG MD-11 and I can do multi-hour long-haul flights around the world without any issues.However, it did require some tweaking:- disable all unnecessary services and background processes. Your idle memory load right after booting should be around 270-300MB- exclude your FSX folder from on-access virus scanning (that one hits performance and uses memory everytime FSX loads/writes a file) after you make sure you have no viruses there- use the /3GB switch- use the /userva switch and push it up as high as possible, i. e. so that the computer boots and starts all necessary services without problems.Depending on your system and hence how much memory you can make available via the /userva switch, you may get enough memory to run your sim perfectly.Worked for me.