Physx and performance

[bulldog0890]

So I'm playing the game at 1920x1080 maxed out with a gtx 780 and core i7. I've found that the game is super smooth except when i'm standing in a room with a lot of fog or smoke. the final offer in particualr is kind of a disaster, seems to jump quickly between 60 and around 30 fps. I'm using the latest nvidia drivers too. anyone else get this.

[Suraci]

I got similar Spec like yours. And I got the same issue. I realized that you can never play PhysX game with just one GPU. Besides, Nvidia never really optimized the PhysX Engine. It looks amazing but it shouldn't cost some much power to run it. So I turn off the PhysX option in this game for 60FPS than some fancy PhysX.

[R234]

Yeah, PhysX was always a huge performance hog. Framerate drops with it on is perfectly normal, even if you had a GTX Titan.

[bulldog0890]

i was thinking of getting a dedicated card for physx, what do you think would be good with that? i could probably get away with something old if all its doing is the phsyx stuff

[Dogg]

When you say jumping between 60 and 30fps I assume you have vsync on yes? Also what AA implementation are you using?

I was getting the same problem on a 4670k and 780 at max until I backed down on the AA. MXAA x8 is a killer and even Nvidia's TXAA at high will be quite a strain. I've found TXAA low to be a happy medium and without vsync (though it is needed due to massive amounts of tearing my end) will get lows of 70ish in heavy Physx foggy and crowed areas.

Hope this helps.

[Stry8993]

Don't have the game, but if any of you remember Mirror's Edge PhysX with Glass breaking, how, no matter what system you had, it just went absolutely nuts. Sounds like it could be somewhat of the same issue.

[Mectron]

i got twin 690 GTX, after much testing, i found out that at max setting i am getting a solid 120 FPS (i have 120 MHZ monitor) and drop to ~100 in physx heavy area (2 GPU SLI, 1 dedicated physx, the las one sleeping). 3 way SLI or 4 way SLI result in a frame drop. (Physx or not)

Running on i7 3770k @ 4.7 and 16 GB of ram. i put Physx to normal for 3D vision and i got a solid 60 FPS with almost no FPS drop.

[Keyboard Cowboy]

Yea frames drop to hell o the final offer, and in some parts of blackgate in the end. There's a LOT of paper and such I can see flying all around in both pkaces. Probably why.

[=Axton=]

Do you guys leave the driver set to 'auto select' what device runs physx, GPU vs CPU? I just checked in game with the display showing which device it chooses and it uses the GPU when auto selecting, maybe using the CPU takes the load off?

[trek554]

Originally posted by Axton:

Do you guys leave the driver set to 'auto select' what device runs physx, GPU vs CPU? I just checked in game with the display showing which device it chooses and it uses the GPU when auto selecting, maybe using the CPU takes the load off?

of course it uses the GPU since that is exactly what its designed for. using the CPU to run hardware physx will only result in worse performance.

[markoh00]

If you are having PhysX performance Problems I recommend to turn the Physx to "normal". There are still some cool effects left but nearly no more framedrops. The performance difference between normal and high is extreme.

[Buck]

Originally posted by bulldog0890:

i was thinking of getting a dedicated card for physx, what do you think would be good with that? i could probably get away with something old if all its doing is the phsyx stuff

i use a GTX 750 TI alongside of a GTX 780 in triplewide (6048X1200). Works well with physx on normal, but still tanks in places when on high.
You'll probably get better results if you're only running one display though

[Psychic]

If you have problems with fps jumping from 60 to 30 or random fps drop (with Vsync on) just use D3DOverrider with triple buffering activated.
The game will be much smoother.
Just like AC4, this game doesn't have triple buffering implemented.

[Buck]

Originally posted by Psychic:

If you have problems with fps jumping from 60 to 30 or random fps drop (with Vsync on) just use D3DOverrider with triple buffering activated.
The game will be much smoother.

But mouse responsiveness is probably going to tank.

[Psychic]

Originally posted by Buck:

But mouse responsiveness is probably going to tank.

Not really, I don't notice a difference. There is probably a bit of input lag, but not noticable.
The game is really smooth with it, since I tried to use D3DOverrider that I can't play without it.

[Buck]

Originally posted by Psychic:

Not really, I don't notice a difference. There is probably a bit of input lag, but not noticable.
The game is really smooth with it, since I tried to use D3DOverrider that I can't play without it.

Keyword ~PROBABLY~.

It is well known that enabling triple buffering tends to have that sort of effect, though there are ways in software to "fix" it, and not everyone notices, or cares.