Hi guys. Quick question:FSX is a 32 bit program. But, if I run this program on a 64 bit OS, can FSX utilize more than 4GB DDR3?

I don't think so but the extra RAM is a good thing as it allows other things to operate (Addons-Windows Stuff) and preventing the dreaded OOM. I use 8GB and I never have memory issues.

No, but the extra memory can be put towards other software, making it quite useful

32bit programs are limited to 4GB regardless of the OS, yes. I've never seen FS use more than 2GB or so total though, even with tons of scenery addons and stuff running.

I have had FSX run out of memory more than once on W7 64, but I suspect some kind of memory leak in one of my many fsx addons. It is fortunately very rare

I have had FSX run out of memory more than once on W7 64, but I suspect some kind of memory leak in one of my many fsx addons. It is fortunately very rare

Out of memory errors in FSX are almost always actually in reference to User Virtual Address Space though, not physical RAM amount...

32bit programs are limited to 4GB regardless of the OS, yes. I've never seen FS use more than 2GB or so total though, even with tons of scenery addons and stuff running.

This having been said, would you say that 4GBs would be enough for my new system? Also, can I use DDR2 and DDR3 on the same MOBO? I bought G.SKILL Ripjaw DDR3, and I still have my old 240 pin DDR2. My mobo has the space, so could I use them all with no problem?

This having been said, would you say that 4GBs would be enough for my new system? Also, can I use DDR2 and DDR3 on the same MOBO? I bought G.SKILL Ripjaw DDR3, and I still have my old 240 pin DDR2. My mobo has the space, so could I use them all with no problem?

No use your DDR3 memory only. When you purchase Windows 7 get the "Professional" or "Ultimate" versions. These two versions have the XP modes with them. This allows your older 32 bit programs to run within Windows 7.William Campbell

You can run 32 bit software in Windows 7 without XP mode.

When you purchase Windows 7 get the "Professional" or "Ultimate" versions. These two versions have the XP modes with them. This allows your older 32 bit programs to run within Windows 7.

Not true at all. "XP Mode" is not the same thing as 32-bit compatibility. XP Mode is an actual virtual machine running a standalone XP install - it's for extremely old apps like 16 bit ones that won't run period in Win 7. Pretty much no one except businesses running really old legacy software needs this.http://windows.micro...windows-xp-mode32-bit compatibility is handled by something called WoW (Windows on Windows) and is present in all 64-bit versions of Windows:http://en.wikipedia.org/wiki/WoW64The average user should buy Windows 7 Home Premium x64. Ultimate or Pro are overkill and not worth the money for features you'll never use.