I am still trying to tweak FSX to my new system. I have NickNs tweaking tips and one step is to update both DirectX and a C++ library update. I checked and my Vista HP system is running DirectX 10. I noticed FSX has a Direct X Preview button. Why a "preview" and should I click it?? Is FSX currently using Direct X 9? Also, when I installed FSX and Acceleration, I know I closed out of FSX before installing Acceleration, but I can't remember if I rebooted the system. Is this an important issue? Am I better to uninstall and reinstall the whole thing? I also don't remember it installing or asking me if I want install the SDK. Thanks. Tom

You don't need or even want FSX running when installing Acceleration. If you think there is a problem run the Acceleration installer again and it should give a repair option. The DX10 mode is a "preview" because they did not get time to fully implement it, therefore it's not fully supported and its a bit buggy. You can certainly turn it on and check it out though. FSX will have to be restarted after you check the box before its enabled. FSX uses DX9 primarily, or anytime DX10 Preview is not checked.

DX10 provides cockpit shadows and better performance on most machines but some have white flashing taxiways in spots where they meet with the runway and some AI packages will show a white airplace instaed of the textures it should have. i personally get better performance with DX10.

A lot of people also get random microstutters every few seconds with DX10: although FSX does run better with DX10 on my computer, those stutters really spoil the experience and so I only use DX9. Also progressive taxi doesn't work with DX10.

I am still trying to tweak FSX to my new system. I have NickNs tweaking tips and one step is to update both DirectX and a C++ library update. I checked and my Vista HP system is running DirectX 10. I noticed FSX has a Direct X Preview button. Why a "preview" and should I click it?? Is FSX currently using Direct X 9? Also, when I installed FSX and Acceleration, I know I closed out of FSX before installing Acceleration, but I can't remember if I rebooted the system. Is this an important issue? Am I better to uninstall and reinstall the whole thing? I also don't remember it installing or asking me if I want install the SDK. Thanks. Tom

Thanks for the help, guys. Does this mean I should change Vista to DX9 since it is using DX10 or do I just keep the DX10 Preview button unchecked in FSX? If I need to, how do I revert Vista back to DX9?? Thanks again, Tom

Thanks for the help, guys. Does this mean I should change Vista to DX9 since it is using DX10 or do I just keep the DX10 Preview button unchecked in FSX? If I need to, how do I revert Vista back to DX9?? Thanks again, Tom

Just untick the Direct X 10 Preview option in FSX. If a game requires DX9 in Vista, then Vista just uses DX9 mode. It's able to fallback to DX9 automatically, and requires no user intervention, or seperate DX9 installation.

Just untick the Direct X 10 Preview option in FSX. If a game requires DX9 in Vista, then Vista just uses DX9 mode. It's able to fallback to DX9 automatically, and requires no user intervention, or seperate DX9 installation.

Thanks for the help Carl. I just heard about NickN's tweaking tips for FSX and downloaded them. He says FSX should be installed first, the system restarted, then Acceleration installed. I remember shutting down FSX, but can't remember if I rebooted the system before installing Acceleration. I just closed out of FSX. Do you happen to know if this this system shut down is important enough that I should uninstall FSX and Accel. and start over, or am I OK? Seems to be running OK except for slow and inconsistent FPS at times. Thanks again, Tom