DCS frames crash unless there is a frame rate cap enforced

[Boosterdog]

EDIT - everything below is bunkum and was speculation on my part. The top and bottom is that - on my system at least, unless an FPS limit in enforced in the NVP (using the "DCS Black Shark" entry regardless of if you use the updater exe) the fps will crash if the low demand in the scene forces the frame rate to spike (ie looking stright up as you are flying at 20000ft). Putting a cap on , even a 300 fps one (which my rig NEVER even reaches in DCS), stops this crash. 

 

Carry on - Nothing to see here.

 

Clean OB 2.7.9 after slow repair and FXO/Meta delete. Can be replicated on (i think) any map and any A/C. Reproduced myself on Marianas, Channel and PG. 

In external view, if I take the camera directly underneath the A/C so that it is looking directly up at the sky, FPS will plummet to 50fps from whatever it was at. As long as the underside of the A/C remains in camera view, the drop will hold. Changing the view to look top down will generally return the FPS to what it was immediately but sometimes this takes longer and i can only get the fps back by alt/entering twice. Checked using FRAPS and in game counter. 

EDIT - tried similar  in other games with the expected results -  the frame rate goes up not down.  Only in DCS am I seeing this. 

Looking to see if anyone else has this or if its my end - if so any ideas on what would be welcomed.

EDIT - this appears to be similar to the previous reports of FPS drops resultant from a halving of CPU use. Rough and dirty on the hardware monitoring shows all temps well under any throttling limit and a restricted use of cores/threads when changing the camera position. Although DCS isnt MC is there a possiblity that it doesnt currently play well with Ryzen's way of doing things?

Usual fliles attached

 

dcs.log fps drop test.miz frame drop AC underside.trk DxDiag 271221.txt

Edited January 1, 2022 by Boosterdog

[Flappie]

Hi @Boosterdog. I cannot reproduce your issue. I replayed your track and had about 40 FPS when looking forward, and ~90 FPS when looking from underneath the aircraft, which seems logical (3440x1440 px).

 

If you want to investigate, the easiest way is to rename your "Saved Games/DCS..." folder so the game cannot find it, and keep it as a backup.

DCS will create a new folder. Replay your track and see how it goes. If you get the "logical" result, it means there's something wrong in your backup folder.

[Boosterdog]

TL:DR - My DCS/Ryzen combo doesnt like running past 200fps.  If I cap the fps to 199  in NCP there there is no drop. If I remove the cap the drop happens. 

@Flappie There was a curious thing about your reply made me look further (the saved games thing didnt work BTW).  If i load up the graphics. SSLR, SSAO etc, so my sysntem was under strain the performance increased if i pointed to sky and stayed there. As you would expect.  If I lower the settings it dropped off. You saw the same expected results because you are beating the hell out of your system as any responsible owner should. I was attempting to keep the system unstressed (too unstressed it seems)

I ran another  mission with the SC. A fully loaded deck with an AI E2. In my low fat, polar bear saving settings as soon a the E2 is at 2000ft, 50fps. With Full fat ice cap melting settings the fps stayed up  until much higher altitude............and then then dropped.

What i noticed though was that immediately prior to the drop the FPS exceeded 200.  So I capped it at 199 in the NCP and the issue stopped being an issue. 

Conclusion - at a point somewhere around or slightly above 200fps my DCS/Ryzen throws a temper tantrum for some reason. 

AS there will never be a day when I will need 200 fps in DCS Im considering this solved but i dont know if its something that may affect higher demand users such a VR'ers in furture.   

Just off to pull a smug face for a few minutes (hours). 

 

 

Edited December 27, 2021 by Boosterdog

[Flappie]

THanks for your precious feedback.

It looks like your Windows Power settings are set to "Balanced" or "Power saver" mode. Set it to "High performance" to avoid any yo-yo.

Edited December 27, 2021 by Flappie

[Boosterdog]

1 hour ago, Flappie said:

THanks for your precious feedback.

It looks like your Windows Power settings are set to "Balanced" or "Power saver" mode. Set it to "High performance" to avoid any yo-yo.

 

Its on a custom power plan. Basically its the high performance one with the suspends on USB, disks and displays also disabled. I reverted to High performance in any case but the results are the same. As is say the other sims I have happly tick the fps counter along at speeds up to 325 fps. 

So whatever it is is tied to going over 200 fps or therabouts. Whether thats a DCS thing I dunno. Going back to the 2.7.6 v 2.7.7 fps drop test i did, I also saw this issue (although i didnt recognise it as such and put it down to FRAPS) when making the basic fps trks. Again, spawing into a light mission saw the fps lock at 50 until i swung about the camera and woke it up.   That was using an I5 6600K which, alongside the performacne in other games, makes me think its more of a DCS core issue than anything else. 

On a side note Im also seeing less performance "oddness" now the cap in in force when entering missions/switching aircraft as it appears that doing so would mometarily boot up the fps to beyond 200 fps and affect stuff sometimes for a second or so, sometimes for longer afterwards. That effect was also apparent in the menu GUI which would lock at 50fps but now sits bang on the capped rate. Again thats something I though it just did!.

Edited December 27, 2021 by Boosterdog

[Boosterdog]

So it appears a frame rate cap - any frame rate cap - solves the issue.

Title changed