well it takes some times but after some research I found a tool to cap every DX9 / OpenGL game at the desired framerate (no DX10 yet sorry)
first you have to download this tool (I'm not sure if this is legal or what, seems freeware to me so mods do what you want)
http://rapidshare.com/files/160642187/F ... er_0.2.rar
extract the content to a folder and run FPS_Limiter_GUI (you must have Java enabled)
it looks like this
[ external image ]
you just need to point to the path where the game executable is located and select the desired framerate, note it defaults to DX9 applications. Click on "create bat" and there you go, you should have now in the folder a direct access to the game limited to the desired framerate.
result: http://rapidshare.com/files/160661014/LP30FPS.mp4
that was a small video of Lost Planet with maximum settings and 8xAA/16xAF capped at 30fps running on my modest PC, it runs silky smooth at a never faltering 30 fps. The best part is both the CPU and the GPU workload is reduced and so is the power consumption, triple win.
and now Fallout 3: http://rapidshare.com/files/160661015/FO330FPS.mp4
with Fallout 3 you just repeat the process and then change the variable iFPSClamp=0 in Fallout.ini to iFPSClamp=30
this is how I got the game to run in ultra settings with 4xAA/8xAF at rock solid 30fps and said goodbye to the hiccups. Hope this helps.
Basically i was using this fix for Oblivion and Fallout 3 , got help from someone else on another forum today. Well i've just tried it on X3 TC and it works really well , problem with X3 is in certain situations your frame rates are up and down like a yo yo. Especially for those that love using vsync ! , well i used this app and capped my frame rates between 30 and 40 fps and it worked really well. Not only did it not stone dive because i was using vsync but the frame's remained steady throughout.
Give it a try! , just make sure you load the jar file and not the exe. Try it with vsync on

http://www.rage3d.com/board/showthread.php?t=33935231
http://www.bethsoft.com/bgsforums/index ... pic=902594