Hello everyone,I want to make the switch to Fs-X on my system but things don't go as planned.Last week, I installed Windows 7 ultimate 64bit on a completely clean and new harddisk. Installed all drivers and updates and find it a great OS.When I installed Fs-X and SP1 I was pleasantly surprised with the overall performance of my not that hot of a system. (Gigabyte GA-EX38T-DQ6 motherboard and Intel E8500 dualcore OC'ed from 3.16 to 4.10 Ghz with 4Gb DDR3 ram, ASUS GTX275 896 Mb, Soundblaster X-fi Xtremegamer fatal1ty pro.)Framerates were up in the 30 in very dense conditions and over 60 in sparsly populated areas.So, pleased with what I saw, I installed acceleration pack too but no other addon's. Gee, that made a difference.Not so much in framerates because that stayed (almost) identical but the overall experience was bad, very bad.When flying over regions with a lot of scenery and/or autogen, sound started to crack (almost like static in broadcasts) and from time to time that became so bad that I began to see gaps and tears in the scenery and even ctd's.So I came down here to look up those symptoms.I found a bit of information but all topics were quite old (2005, 2006). Some of those topics suggested to check latency (DPC latency checker).After some more experiments I found that thare is a huge latency (checked with DPClantency checker, latency goes up to 15k

Luc,You'll find the best FSX and system tuning information here: http://www.simforums.com/forums/forum_posts.asp?TID=29041

Luc,The DPC latency issue is a hardware/software issue and happens when the PCIE bus gets overloaded. The only thing you can do to combat it without changing your OS is to reduce your autogen slider or if you have a video card that has at least 1GB of RAM, try adding the Bufferpools tweak to your fsx.cfg file and use a very large poolsize. By large I mean some where between 250MB to 400MB that is 250000000 to 40000000 respectively.I orginally found this issue when I was running under Vista 32, had it under Vista 64 and since upgrading back to XP x64 the issue has since disappeared. I run XP x64 solely for FSX and use Windows 7 x64 for everything else.

Luc,The DPC latency issue is a hardware/software issue and happens when the PCIE bus gets overloaded. The only thing you can do to combat it without changing your OS is to reduce your autogen slider or if you have a video card that has at least 1GB of RAM, try adding the Bufferpools tweak to your fsx.cfg file and use a very large poolsize. By large I mean some where between 250MB to 400MB that is 250000000 to 40000000 respectively.I orginally found this issue when I was running under Vista 32, had it under Vista 64 and since upgrading back to XP x64 the issue has since disappeared. I run XP x64 solely for FSX and use Windows 7 x64 for everything else.

Sargeski,That sounds about right on the mark.However, I wonder what is causing it. Before SP1 I have no problems whatsoever and it's only after I instal the acceleration Pack OR SP2 that the latency occurs.And is the bufferpool tweak only for those who use a card with 1Gb or more, or does it help all cards?And I have another thing on my mind.If it's really the PCIE bus that gets overloaded (and I don't doubt that or have an indication that points in another direction) I wonder why other people don't have this issue?The pcie bus has a standard setting and cannot (as far as I know) be overclocked..... If that is true, what causes the overload for

...I wonder why other people don't have this issue?...Luc BrusselmansBelgium

Think a LOT of people have that issue, myself including. It

Sargeski,That sounds about right on the mark.However, I wonder what is causing it. Before SP1 I have no problems whatsoever and it's only after I instal the acceleration Pack OR SP2 that the latency occurs.And is the bufferpool tweak only for those who use a card with 1Gb or more, or does it help all cards?And I have another thing on my mind.If it's really the PCIE bus that gets overloaded (and I don't doubt that or have an indication that points in another direction) I wonder why other people don't have this issue?The pcie bus has a standard setting and cannot (as far as I know) be overclocked..... If that is true, what causes the overload for

There is a really simple fix, lock the framerate at 30 or below and it will stop, its the vastly fluctuating frame rate that causes the crackling sound. You can try adjusting the sliders so that you get a nice average of around 30fps and this will also work. If you look closely you will see as the frame rate gets above 45 or so in spikes that's when the sound starts to go funny, its especially noticeable if you switch to an AI aircraft view, the sound starts to warble.

One thing that you should also consider is going to your sound settings dialogue in control panel and reduce the sound quality.I have had to turn down the sound quality on my Creative Xfi card to CD quality, due to various memory issues with PMDG stuff.

Sigh, FSX, built to outlast powerfull gaming pc

Wow,there's a lot here to think about.I will try the bufferpool first because that seems to be the only path available to me now, except maybe locking the framerate at or below 30.Some other sugestions I have already tried. Installing in windows XP 64bit doesn't change a bit. Same latency and same crackling noise. That's also true after reducing the sound quality of my card. Even on CD-quality I get the sound distortion.I will just have to wait until I can assemble a new system. That's probably in the course of 2010 so patience is a virtue in this matter.What I did expect though but never read in the answers was somebody sugesting to upgrade my asus GTX 275 to an 285...Is that part of the solution? It would make it easier to work with the bufferpool solution I guess but would it really make a difference (for my problem I mean because I do realise that a 285 card is more powerfull)AnywayI want to thank you all for the contributions.I wish you all a nice christmas and a prosperous 2010 (and lots of good landings)Luc BrusselmansBelgium PS If I do find that swwet spot... I'll let you know