Question Physics performance worse following GPU upgrade?

[Chromatose]

Howdy! First post here, hopefully someone else has run into this and can lend a hand

I recently upgraded my GPU from a 1080 to a 3090. In VR on a HP Reverb G2, I've seen a noticeable improvement in 1 & 2 person scenes, and can run 1.25 render scale at ~45fps+ which is comfortable for me.

However, I have a 3 person scene where overall framerate has tanked following my GPU upgrade.

With my 1080 running downscaled by 75% I'd get about 40fps in this scene. With my 3090 I'm only hitting 20-25fps, regardless of what I do to my render scale and light settings. The performance monitor shows that the physics update is taking some 20-25ms.

Any ideas why physics performance would get worse following a GPU upgrade? Only thing I can think of is if there's some kind of weird thread synchronization issue I'm hitting now that the GPU isn't the bottleneck in this scene, but some quick fiddling with physics update rate settings doesn't seem to have much impact.

Thanks in advance!

 

[TToby]

Hi,
first thing to say is, that most of that problems with performance and fps drops in VaM is because of its poor CPU multi-core usage, especially with physics. As it is mainly a CPU bottleneck (that just can't be helped much in this current versions even with a monster CPU), you maybe have cranked up some graphics settings here and there for your new GPU and therefore will have worse fps. Please take a look at the recent performance threads, too, as many VaM users have updated their hardware to the max and still have some stuttering because of the old Unity engine VaM uses.

Ok,
from now on it is highly speculative:
Some month ago, I had updated to a brand new 6900xt watercooled monster GPU, too.
I am not completely sure anymore, but I think I also had some issues with physics, stuttering and fps in VaM. It was very obvious with animations, for instance, though maybe because of body, hair and clothing physics while moving around a lot. Fps drops and stuttering, more than with my old GPU!
I have tried out some settings and instead of lowering the performance relevant settings,
I ended up by putting everything to the max. This was solving the issues for me!
IMHO, the GPU was maybe simply too fast for that old physics engine... lol.
(This may be not completely rubbish, because something like this was a common issue with older game engines like in Fallout(VR) and Skyrim(VR), so that some users had to cap their fps at a certain maximum).
With supersampling at 200% and the knowledge that many of the fps issues in VaM comes from the bloody single-core CPU bottleneck, I am happy now.
Though, I did a lot of driver updates in that time, too... so I am not exactly sure of this being the only reason.