"look back" view - massive FPS drops, anyone else experienced it?

[Lizard Of Bodom]

Hi all
I am experiencing massive FPS drops when using "look back" button - I normally play in "cockpit" view with steady 75FPs but when looking back, it can drop to sub 50 for example. I always blamed my SLI setup (you can clearly see both cards utilisation is dropping to 60% or around but SLI sync is still "1") but recently experiencing other issues aswell and just want to confirm if anyone else with single/dual setup have similar problem?
Once I stop "looking back" view is back to 75FPS steady. Makes no sense as fps drop happens even when I am rear-facing wall and there is nothing to render.
It seem to me like a bug/incompatibility, similar to sparks issue, but any feedback appreciated.
thanks
(Ryzen 3700x+32GB+GTX980SLI)

 

[Billy Pilgrim]

When I look back, there’s no noticeable drop in FPS. I use a single gfx card, but used to use gfx cards in sli and as far as I remember there was no FPS loss when looking back.

 

[Lizard Of Bodom]

Thanks for input Billy.
Also to whoever reading it in future with similar problem - it IS some sort of SLI issue, as expected, caused by "particles FX" part of CSP - in particular, the "new smoke and dust" section. Oddly with this one small option "active" it can create all sorts of issues even when car is stationary. I knew "sparks" can cause issies for SLI, have them disabled ever since I noticed it cause massive FPS drops on every contact with barrier, but obviously there is more to it.
with Particles FX inactive, there is zero fps drops when looking back and whole gameplay is much smoother in general.

 

[Michael Krone]

Thanks for input Billy.
Also to whoever reading it in future with similar problem - it IS some sort of SLI issue, as expected, caused by "particles FX" part of CSP - in particular, the "new smoke and dust" section. Oddly with this one small option "active" it can create all sorts of issues even when car is stationary. I knew "sparks" can cause issies for SLI, have them disabled ever since I noticed it cause massive FPS drops on every contact with barrier, but obviously there is more to it.
with Particles FX inactive, there is zero fps drops when looking back and whole gameplay is much smoother in general.

Do you think these problem exist with single card setups? Any CPU abnormalities with particlefx that you notice? Ive been dealing with some issues recently and I believe it to be caused by this option...

 

[Lizard Of Bodom]

Do you think these problem exist with single card setups? Any CPU abnormalities with particlefx that you notice? Ive been dealing with some issues recently and I believe it to be caused by this option...

No idea to be honest - I see no reason for this to behave like this for "normal" setups so I tend to blame anything on SLI (it is, in most cases!). If you have problems, do what I did - turn off all extra CSP settings in Custom Shader Patch (just unclick "active" per each main category and run benchmark test for 10 seconds. Then enable 1 section, run benchmnark again. etc etc, thats how i discovered this, as most options will reduce your framerate by 2/3 fps, but particles FX was making it 50% fps drop.
The other HUGE culprit i found out was "allow color buffer" something in the "graphical adjustment" settings. Its enabled by default if i remember correctly, and it made my FPS drop from 125 average to 35 (yes!). Again - I suspect its because SLI setup but cant say for sure.