Hi Ric;
If you're specifically talking about white squares and black flashes - they can usually occur when the texture to be shown doesn't have time to display - or simply is missing. You can find the missing texture by turning Missing Texture detection on in the Fixer (or ShowMissingTextureAlert=1 under [Display]in the fsx.cfg).
Much of our FSX problems come from a combination of all of your settings. I
can tell you - I run 5.0 gig with a 780, and only run 4x SGSS, because it's one of the hardest variants of SuperSampling AA that there is. 4.5 LOD, too, and very modest traffic. 4x SGSS is "ok" for yours, because you
do need decent AA - and that will give it to you, but you have to make compromises if you want to see 30 continuously. 8x will cripple FSX. This completely prevents running nice clouds, water, "NGX"-type aircraft, "London", "Seattle", "Paris", "New York" - all the "heavy" aircraft and scenery's that makes the sim shine! It stops you going from 1280 x 1024 to 1920 x 1080, though hardware comes more into play there.
Trying "with" and "without" BufferPools means a lot of testing, too, Ric: one cannot just turn bufferpools on or off. If you remove the section from the fsx.cfg - you have just set your graphics buffer control to "UsePools=1" and no reject threshold. 4.4 gig and a 680? I would have UsePools=0 and never change it.
UsePools=1 means you control the parameters and buffer type:
UsePools=0 means the gpu controls the parameters and buffer type.
If UsePools="0", then water may be set to 6 to fix it. I'm not particularly convinced that that is
the answer (Bojote mentions "cloud flashing caused by the "0" "), as Swap_Wait_Timeout is in there, along with FFTF and a couple of other testable parameters, like Maximum Pre-Rendered Frames (Inspector) - it's in there too.
Lastly - your use of the words " I am still getting white squares and black squares occasionally" is a very subjective comment, and is one of the "compromise" and "expectations" issues that one
either accepts, and gets on with the flight, or one gets hung up on, and it ruins the flight. If there was a "correct" and "known" fix, Ric - I'd be the first here with the news, but it's just not as simple as I or we would like. You need to set up "the test flight" and test, test, test, until suddenly - the flash doesn't happen. In electronics this has to be repeatable, too, so that you can be sure that you have, indeed found the cause.
... sorry - I'm afraid it's another long-winded post..... (sigh)
All the Best,
pj