Hello, Tom, and welcome to All Aircraft Aracade!
The ATI 5770 with a Quad Core computer system probably can handle maximum graphics settings. You should use Vertical Sync OFF only for Benchmarking and begin Optimization with Vertical Sync ON. You also should have Vertical Sync ON in the end.
Clip Hint has much to do with clouds. When Clip Hint is marked, this enables the graphics system to anticipate things which will appear from behind (and also along the edges) of clouds and a few other objects. When the viewer is in motion while looking at clouds with textures in the background, then Clip Hint allows the best creation of the image. The graphics card can only make appropriate and realistic rendering of motion in relation to clouds and textures with Clip Hint ON. Some very strange artifacts are possible with Clip Hint OFF. I recommend Clip Hint ON for all IL-2 users.
Texture compression ARB extension can benefit some users by increasing performance with little decrease in image quality. However, some graphics drivers reek havoc with this ON, especially with Clip Hint OFF. Therefore I am not surprised by the "clouds flicker" and "small side vibration", which are typical symptoms of your current settings of Clip Hint OFF and Texture Compression ARB Extension ON.
1) Turn Clip Hint ON. That might solve the whole problem.
2) If that does not work, then turn OFF Texture Compression ARB Extension.
3) Your Quad core system should be able to use two of your cores for IL-2 and Multi-Threading ON.
I recommend the use of number 2 and 3 cores for IL-2 in your Quad Core system. You might see benefit of assigning IL-2 related programs to the 4 core. This keeps them separate and they will have much less interference with one another.
In your
conf.ini file, try this command line value: ProcessAffinityMask=12, makes core 2 and core 3 process IL-2.
You can assign IL-2 related programs such as TrackIR, HyperLobby, and TeamSpeak to 4 core and keep them separate from IL-2. You would use a program called Prioaff to do this. It has an execution application called Prioaff.exe which allows you to assign any program to a specific core.
Windows Task Manager can be used instead to assign a program to a core, but you need to reassign each time you restart your computer.
Many people can get the best by assigning IL-2 to one core and the other programs to different cores.
Managing Multi-Core Systems and Assigning Programs to Cores with Prioaff.exe
http://mission4today.com/index.php?name ... ow&kid=422
If you want to keep it simple and not change the process core assignment, then that is all right, but getting the best for your system might require changing the Process Affinity Mask in the conf.ini file.
Let us know how things go and if you have any questions.