Why massive FPS loss when streaming ?

[smokey_1]

I'm just trying to find out why in some games (pCars and GTAV) I see big reduction in fps when streaming, wheras if im not streaming and playing in the host machine, fps is much higher.

I'll explain what I mean:

pCars running on host and fps is generally 75-90fps at my settings(all maxed 1440p).
However if im streaming to my streamlink (1080p 60fps) then fps is fluctuating 50-60fps.
Why is it not locked to 60fps if the host machine is more than capable of maintaining it?

I tested nVidia Hardware encoding "game polled dx11 with NVEnc" which is what above example is from.
Software and Quicksync are even worse than NVENC.

GTA V is the same, host can be capable of 70-90fps but in the same area of game if streaming fps will be low 50's.

Other games ive got, Alien Isolation, MGSPP, FC4 are ok (but granted they are less demaning).

Rig is:
Win 10x64
4770K @ 4.6ghz
GTX 980ti @ 1500mhz
16GB ram @ 2666mhz
Z87 mobo and 850Pro SSD's
Killer NiC

Hardwired through R7000 Nighthawk router (input and stream <1ms latency, video ~25ms) to Steamlink.

Steamlink settings 1080p,beautiful,unlimited bandwidth.

Streaming quality is great with video usually 25-30000 kbps and latency nice and low (as above)

Just those annoying fps drops in some games when the host rig is easliy capable of maintaing >60fps on its own.

Does the streaming place extra load on the GPU or something?
I thought Maxwell offloaded all the encoding. For example Shadowplay can record video with next to 0 fps loss on my rig.

For what its worth whilst streaming I have used my phone with remote monitoring software to check GPU ( inc Video engine) and CPU load, Network throughput.
Nothing is maxed out (bottlenecking) when im seeing the fps drops.

What could it be ?, its really ruining my streaming enjoyment.
In other games as ive said its flawless and youd be hard pushed to tell you were not playing directly on the host!!

[Seleuco]

Same here. I have a better experience in Windows 7, but Windows 10 is horrible with GTA V. Low frame rates.

Anyway, this is beta. They are improving it.

As far I know, frame capture is done in sw, they are going to move to GPU.

So wait till then.

Also you can get out from the beta branch. In release branch they are still using nvfbc that not have frame rates issues although is a little buggy for me.

[kreiselhoschi]

Just an educated guess: disable unlimited bandwidth.