I tested this on vanilla FSX (fresh install) with SP1, SP2, and a week ago with Acceleration FSX setup. So I can't blame Acceleration, tons of addons, or my hardware (I suppose). When I start a flight, or my test situation with default C172, DPC latency is acceptable, but still way higher than normal (everything below 500):

 

 

 

After a 20-30 minute flight, DPC tends to go higher, and on approach it looks like this:

 

 

The sound start popping and crackling because of high DPC latency, and some stutters appears, which is completely unnaceptable.

I tested this issue a bit further and on next approach when latency was pretty high, and even higher (up to 8000), I went to settings and changed autogen density from Dense to Normal. Guess what, dpc latency was in green all around! Just a one notch left with the autogen slider and latency gone away. Then after I saw that quite surprised, I want back to the settings, and set the autogen back to Dense, and also to my surprise dpc stayed in green, on approach! Since I've tested this yesterday I'm quite confused and puzzled what is happening here with DX9 mode and autogen batching, or something. In DX10 mode DPC latency is not a problem, stays very low in green all the time. But in DX10 I have problems with stutters, not nearly as smooth as DX9 (when dpc latency is acceptable).

 

So I prey for help guys, because this is clearly a fault in FSX. I tested few other games, no latency at all. I reverted my CPU and DRAM clock to default, no difference at all, so it's not hardware or overclocking. Maybe my Win7 64bit and drivers are messed up, but I can't test that, unless I delete and reainstall Win7 completely, which is quite time consuming, especially considering that I have bunch of software for work.

 

I experimented with BUFFERPOOLS for days, and the results are not the best, I lowered the latenvy a bit, nothing spectacular. By the way, the result with BUFFERPOOLS you saw above on the first image. Without BUFFERPOOLS dpc is even higher with default C172. I tested some other tweaks as well, but the latency stayed the same.

 

So I guess there are some tweaks for autogen batching or something in fsx.cfg that could help to maybe eliminate dpc latency? I can remember that I saw some tweaks in fsx.cfg for autogen that I didn't saw never before, but I can't recall where I saw them. I just know that I saw some lines with "batching" word in it, and I guess I can experiment with those tweaks a bit.

 

Any other suggestion guys? Why autogen is making these problems with dpc latency? I'm quite sure there is quite a few guys that knows good a FSX architecture and how the autogen batching works, or maybe even the problem with dpc latency.

 

 

So I will appreciate any help A LOT, really really. As you can see I'm stuck with FSX, can't use DX9 (dpc latency) and DX10 (huge stutters) without problems.

 

 

Cheers and thank you!

I'm not sure I can help but tried the tool with FSX DX9 (i do not use DX10) and latency for a normal 15 mins flight in ORBX scenery, (detailed airports, max everything ) is on avg 43 us.

To put the results in perspective FSX DX9 is running smoothly.

So, we obviously have very different setups, but in your case there are bottlenecks. Locating them will be the trick.

It is the first time I use that tool (thank you by the way) and will experiment further.

I'm not sure I can help but tried the tool with FSX DX9 (i do not use DX10) and latency for a normal 15 mins flight in ORBX scenery, (detailed airports, max everything ) is on avg 43 us.

To put the results in perspective FSX DX9 is running smoothly.

So, we obviously have very different setups, but in your case there are bottlenecks. Locating them will be the trick.

It is the first time I use that tool (thank you by the way) and will experiment further.

 

Yep, I also think that latency is a bottleneck of some kind. But the fact that latency is present only in FSX DX9 is killing me. If the latency is present in every game or app, I would know what to do.

Could it be that DX9 maps video memory into the VAS differently than DX10 does?

Latency in DX9, stuttering in DX10 - maybe different symptoms of the same underlying problem? Does your DX10 stuttering problem go away with reduced autogen?

Latency in DX9, stuttering in DX10 - maybe different symptoms of the same underlying problem? Does your DX10 stuttering problem go away with reduced autogen?

 

No, I've tested also without autogen, still stutters. But you made me to think globally, maybe after all it is some kind of drivers/hardware problem/mess.

I had a problem with latency awhile ago. Personally when I had someone build my computer they plugged my hard drive into a backup connection on the motherboard. I switched the connection to the other one and latency went away. Not sure if this is your problem but it was mine.

I had a problem with latency awhile ago. Personally when I had someone build my computer they plugged my hard drive into a backup connection on the motherboard. I switched the connection to the other one and latency went away. Not sure if this is your problem but it was mine.

 

Hmmmm, that's interesting. I keep my FSX install and everything that goes with FSX (Addons) on a separate 7200rpm SATA hard drive. But again, why wrong connection for a hard disk would have a impact on a latency ONLY IN DX9? That is bugging me. Something is triggering huge latency in DX9, and I must understand FSX architecture a lot to find a reason. DX10 mode is using GPU a lot more, maybe DX9 is using hard drive a lot more, because the textures are processed by the CPU more than a GPU, who knows. Two many variables to play with, that's why I called experts for a help. :excl:

 

On a side note, what is a backup connection on a motherboard? I only know for a primary and secondary connection for ATA and SATA drives, nothing with backup name on it.

I only no the man might have connected it to a the wrong connection.

Solved it, oh yes! Nvidia Inspector settings created the issue, unbeliavable! And I was hitting my head for months to find what is causing dpc latency, and I never thought "let's delete ms flight simulator x profile in inspector just in case". I'm so stupid! Interesting stuff is, that some of the settings were connected to the autogen density, causing higher dpc latency with higher autogen settings. Probably some mess with antialiasing transparency or something, God knows.

 

So, keep you nV inspector settings at apsolute minimum, don't play with it too much!


Cheers

Solved it, oh yes! Nvidia Inspector settings created the issue, unbeliavable! And I was hitting my head for months to find what is causing dpc latency, and I never thought "let's delete ms flight simulator x profile in inspector just in case". I'm so stupid! Interesting stuff is, that some of the settings were connected to the autogen density, causing higher dpc latency with higher autogen settings. Probably some mess with antialiasing transparency or something, God knows.

 

So, keep you nV inspector settings at apsolute minimum, don't play with it too much!

 

 

Cheers

So let me get this straight... You deleted your MS Flight Simulator X profile via NVidia Inspector. You created a new FSX Profile with NI and restored all you same settings? Voila! No more latency issue?

So let me get this straight... You deleted your MS Flight Simulator X profile via NVidia Inspector. You created a new FSX Profile with NI and restored all you same settings? Voila! No more latency issue?

 

Yes, with one difference. I deleted MS Flight Simulator X profile, created profile named "FSX", and applied only minimal required settings (8xQ AA, 16xAF, Clamp Lod Bias) and that's it! Also in Nvidia Control Panel I found a profile for FSX, with the same settings as in NV Inspector, maybe there was some conflict.

 

At least now I can now relax and enjoy simming! No more pointing fingers at FSX, hardware, etc.

The Nvidia profile should be the same as the Nvidia Inspector profile, they both edit the same settings.

Interesting observations.  Thanks for sharing.  I'll have to check out my own system.

The Nvidia profile should be the same as the Nvidia Inspector profile, they both edit the same settings.

 

Yes. But I don't know will control panel automatically match the settings as in nv Inspector?