Multi Monitor - 1 or 2 Gpu

[DerekBlueEyes]

Intro
I already know dual GPU, with setup GPU-1 on game and GPU-2 as encoder is not helpfull for streaming.
Now we can move on.

Status

CPU: i7-6700K stock 4.0Mhz -> OC @ 4.6
GPU-1: MSI GTX1660 Ventus XS OC
MOBO: MSI Z270 Tomahawk
RAM: Corair Vengeance RGB PRO 32GB 3200 MHz
SSD: Samsung M2 970 EVO 500GB
MONITOR-1: AOC Agon 23.8" QHD 2560x1440 144 Hz
MONITOR-2: Acer 23,6" FullHD 75 Hz

GPU just upgraded from GTX980 Gaming OC, still available, from now on refer as GPU-2

Goal
Game on Monitor-1
OBS dashboard on Monitor-2
Good performance on both process with priority on game

Question
Make sense, to achive the best performance on both gaming and streaming, to put both GPU inside the PC and use GPU-1 for Monitor-1, GPU-2 for Monitor-2 (to unload the GPU-1, that right now handle both monitor) and use GPU-1 to encode too?

Thanks in advance

 

[carlmmii]

Just take GPU-2 out entirely.

Just having a 2nd GPU in your system reduces the PCIe bandwidth available to your main card, even if you don't have a monitor connected to it. 3.0x16 -> 3.0x8 for both cards.

With a monitor connected to your 2nd GPU, you're now having to deal with framebuffers sent over the PCIe bus, further congesting things. Driving a separate monitor for display purposes is a very small load on your main GPU, and not something that should be a concern nowadays.

Just take out GPU-2, connect both monitors to your main GPU, and use your main GPU for encoding. That gives you full PCIe bandwidth, and allows the new Nvenc to keep the framebuffer entirely within the GPU for encoding purposes, which further reduces PCIe bandwidth.

 

[DerekBlueEyes]

I had the same idea (in fact the currently setup is only with GPU-1, I never had 2 GPU in my build I just started thinking about it) but just disabling the obs preview during streaming gave me back 10fps in warzone.
So I'm not sure the the second monitor is a "very small load on your main GPU" to be fair.

 

[carlmmii]

Post a log file. There's quite a lot going on with "just the preview" -- OBS still has to do all the compositing. OBS is an actual load. Just driving a display is not.