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DX10 and REX Essential+Overdrive - Framerate degrade

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I finally tweaked FSX to a knife edge using the How To guide and forum suggestions. Most of my A/Cs yield a steady 29-30 fps in all but the busiest scenery areas where I'm able to maintain low to mid 20s. My addons all work during the daylight hours but the fsdreamteam airports crap out after dark. LAX v2.0 was optimized for DX10 and works great regardless of time of day. All was good in the world and even my PMDG 744 smoked.


Then I upgraded to REX Esentials +OD. I immediately saw fps drop to 15 and every time the weather engine refreshed, fps dropped below 10!!! I've backed down everything that can be backed down forsaking the HD texture loads, minimized the LOD range, the cloud draw range, the percent cloud fill and every conceivable texture and terrain variable with a very marginal gain in performance. The only thing that worked was to turn off the weather engine and resort to static real world or 15 minute wether updates via FSX's weather page.


To make matters worse, I started getting CTD's caused by video and system memory conflicts. Resetting LOD to 4.5 from 6.5 fixed this problem but I seem to be taking leaps backward instead of forward regarding DX10. Going back to DX9 solved most of the daylight scenery issues and REX's weather engine yielded frame rates in the 15-20 fps range with most of the sliders edged slightly back to the right.


Turning off REX's weather engine offered the most bang for the buck as far as frame rate was concerned. I even was able to reload the HD textures at 4096 without a performance hit (except in busy scenery areas where 20-25 fps was realistic). Using the HD textures still caused CTD's but they were solved by tweaking BP, RTD and leaving LOD at 4.50.


Right now my options are:


1- Enable DX10. Turn off REX weather injection, use HD textures and scenery at a slightly shorter range of detail and get the 28-30 fps I'm looking for.


2 - Fall back to DX9. Turn on REX weather and accept lower performance and less realistic scenery.


3 - Enable Dx10 and Rex weather, back down scenery and weather and accept the performance hit.


I have to say that the REX weather visuals are absolutely stunning - the best I' ve seen! If anyone has a solution or can suggest tweaks that can get me back to frame rates in the 25-30 fps range I'd be forever grateful. I have a pretty powerful system that is stable at 4.6 GHz with 16 GBytes RAM and an EVGA GTX 560ti card. I run FSCommnder 9.2 on a second monitor but I don't think that accounts for any of the performance issues. I have a good case and great cooling with core temps in the 40C range while throttled up.


Any thoughts or suggestions or if you can think of anything I've overlooked please pass it on.



Rick Bertz

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Hi Rick,


after you changed that all have you tried to let the system made a new cfg file?

sometimes it helps.

Furthermore I had in the past the same problem with REX.

Still I wanted to have a better look so I went back to FEX (the developper was the ceo of orbx)

Put in Nick Needham;s sky and water textures and choose for the soft clouds.

I put the sliders back of the weather and man I have the greatest and nicest what you can imagen.

It is an alternetive for you framerates drop and have a very nice picture, but yeah in general speaking the weather takes

a hell of a lot fps.

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im with 3ghz and 260m-gtx 4gb ram ; my rex is ;


1024 3d clud dxt5

1024 cirrus

512 water

dxt1 wave


and dx10 tick at water/sun flare

dont forget the install textures while fsx not running


you should chek TEXTURE_MAX_LOAD= section to depends on your texture pref...


honestly i found 1024 textures very good at performance/quality


dont forget to change ''water changes'' to ''no change'' while using rex engine and ''disable turblance effects on aircraft'' tick ''download wind'' untick (these are recommends of rex manual)


*''vx refresh balance every 2.0sec'' can helps while rex injecting wather drops less fps


im playing at 1366x768 30fps limit with vsynch

Fxaa on not any other antialias (its fast and efficent)

16x aniso


no autogen (i dont like it :P its making unrelated architectural buildings at mediterranean scenerys)


bloom (awsome :) its my must be :P )

special effects high

level of detail radius medium


very dense scenery (in most scenerys especaily at airports ''extreme'' just adding another same ship/static cars/unnecesery models wich is alrdy exsist at scenery with dense... its not fun too see same car/bus next by next over and over again in parking lot or at apron...''extreme'' is pure performance killer with no sense...)


all aircraft shadows

no ground scenery shadow

water effects mid 2x (venice dont like above :P )


cloud draw distance 80mi (more=perf drop badly + alredy cant see futher with maximum coverage + cirrus clouds cuttin at middle above this wich is buggy looking)


cloud coverage maximum

no any road/ship trafic (pure performance killers)

%50 aircraft traffic



















with these setting i nearly always get 30fps + on ground...lose fps to maximum 22-18wich is also rare (happens at mega airports sometimes but not always)... your system more superior than mine you must have constant 30fps with these settings...


also i suggest do tests like mine for buffer pool setting i found wrong setting causing perf. drops identical


*dont forget nvidia 320.18 drivers... they come out couple of days ago...

i hope these helps a bit :)


i also have some issues with rex wich is its injecting weather every minute ! wich is droping my fps periodicly... i think its cause of vxplus mode.. but every minute why???...

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Rick, are you using the new WXPlus mode for weather injection, or the older mode?  I quit using the WXPlus mode since it continually updates and loads the weather in to the sim, naturally using up resources.  I remember reading somewhere on the REX boards that WXPlus mode is not the ideal integration with FSX.

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Thanks Guys-

I'll look into your suggestion.



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We are coming out with SP2 this week which adds more options to WXPLUS mode per user feedback.

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We are coming out with SP2 this week which adds more options to WXPLUS mode per user feedback.



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Thanks for all the suggestions. After a lot of T/E I've narrowed the performance hits accountable to REX Essential to frame rate only. I use the REX texture files and tweaked the CFG file to accept the HD graphics tiles at a LOD of 4.5 with most of the in game sliders to the right. I no longer get CTDs 15-30 minutes into the flight but either of the REX weather engines result in substantial frame rate losses.


Until they come out with Service Pack 2.0 I'll just turn their weather injection off and resort to the FSX in game real world weather. This gets me an acceptable frame rate of 30 in all but the busiest airports where they drop to the low 20s. Very good graphics all around.


I also resorted to flying DX10 during daylight hours only and reloading DX9 if I feel like doing long distance or night flying. I think there are a couple of people working on the DX10 texture issues and I will follow their posts for any changes. I have to say that the DX10 textures and graphics are really superior to DX9. I hope that the airport problem will go away as more and more of us settle on DX10.



Sent from Rick 's iPad using Tapatalk


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We are coming out with SP2 this week which adds more options to WXPLUS mode per user feedback.


is this mean its gonna stop injecting weather every minute?

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It's not every minute, it's every two minutes currently, and yes we are giving more options in regards.

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I reduced the clouds to 1024x1024 and my framerates are back to 25-30. I can't detect any difference in the image quality at this setting and the sim runs flawlessly. Give this a try and let me know how your visuals workout.

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Does this only affect those of us who choose to use REX as a weather engine? Can I disregard this since I use opus for weather and REX OD only for textures?


I'm new to DX10 and still learning as I go as to what I can or can't do.

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It only affected me when using the REX weather engine - not their textures. I lowered my texture resolutions to 1024x1024 and it solved most of the frame rate problems I was having. I'm back to +/- 30 in quiet ares and 18-25 in busy ones.

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