Steam FSX config vs "Classic" FSX

Bjoern said:
I've done a bit of testing in FSXSE last night (well, I've tested all night long...). BP=0 does indeed give a mild performance boost, but I get occasional, flashing white artifacts on the terrain. Bumping up water from 2.x low to 2.x high, as generally recommended when locking out bufferpools, does help, but comes with a performance hit that negates any frame rate improvement.

And surprisingly enough, I do get better results without any custom poolsize numbers at all! DTG apparently really made some improvements to the handling.

One thing left over from FSXMS that can be worked with surprisingly well, however, is the "RejectThreshold=" line in the [BufferPools] section. This (AFAIK) sets a size limit for what models go into the buffer and what models go directly from the CPU to the GPU. Sane values that can be worked with are anything from 128 KB to 1 MB.
For me, the best compromise between framerate and smoothness is a value of 524288 (i.e. 512 KB - 512*1024). I assume that due to this treshhold, higher poly AI models (model file size >512 KB) and the user aircraft (model file size definitely >512 KB) take the shortcut to the GPU, while lower poly models (clouds, buildings, cars, the remaining AI aircraft) are buffered before they're further processed. This should ease input/output stress on the buffer while avoiding chocking the GPU bus with a lot of simulatneous, instant rendering requests.
In any case, I was surprised how much the 512 KB value improved my "performance nightmare" (NYC) scenario.

A job well done from DTG. Save for AffinityMask, the RejectTreshhold tweak is the only (performance-related) thing left over from my old FSXMS config.


The rest of my tests revolved around anti-aliasing and anisotropic filtering and its performance cost. My compromise solution for my system and settings is AF enabled in FSXSE and 16x AF set in NvidiaInspector. AA is off in FSXSE and is also set in NI via "Override Application Setting". The mode is Nvidia's "8S", which applies a base "1x2" supersampling to the rendered image. This softens up edges on parts with alpha channels (fences, etc...). The mode then adds 4x multisampling to further refine parts without alpha channels. This overall produces a better image than 8x multisampling, because any transparency anti-aliasing mode won't work when FSX(SE) is running in DX9 mode.


Well, thanks for making me investigate. I otherwise would have used my old tweaks till St. Neverwhen's Day.
Click to expand...

Good info - thanks!
 
Another tweak that's discussed at Avsim is "SmallPartRejectRadius", which can be added to the FSX.cfg's [Scenery] section. It affects airport vehicles and AI models and the default value is something like "4". Setting this to "0" will make FSX start rendering said models at a far distance from the user aircraft at the cost of a few FPS, while values larger than 4 will make them disappear much earlier, thus improving visual performance. Setting it to 6 or so (as I did) definitely helps over very busy areas like NYC-
 
Just started a flight over a rural area. Not smooth, not smooth at all. Which is odd, because there's not much AI around. Quit FSX, threw the "RejectThreshold" line out of the fsx.cfg, restarted the sim. Rural airport - smooth. "Frame rate hell" scenario - smooth flying a circle (objects need to be loaded).

Wow, you really don't need to tweak FSXSE anymore*!



*Save for AffinityMask and SmallPartblahblah.
 
That's really good news.
If I ever have to reinstall FSX one day, it will be the Steam edition and not the disk one.
 
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