Question / Help FPS Drops

Skullwar

New Member
Thanks for taking the time to read this!
Lately I've upgraded my GPU and to Studio so I'm pretty new to Studio.
Hardware: CPU- AMD FX-8370 8-core
GPU 1.) GTX 1060
GPU 2.) R9 290X
I kept the 290x in might as well use it instead of gathering dust.
I'm using the AMD Encoder which seems to work fine, I'm running 3 monitors, 1 on the 1060, and the other 2 on the 290x.
OBS usually captures fine a few game capture glitches here and there but fine all through. 720p 60fps

Questions: Why when I'm playing I lose anywhere from 10fps-30ish fps?
Also, why does OBS use anywhere from 5%-12% CPU usage?



Thanks!
 

Skullwar

New Member
Bump.

Further update~
I switched to the NVI. encoder and works a lot better.
Is there anyway I could use the R9 to encode??
 

GespenstMkII

New Member
GPU 1.) GTX 1060
GPU 2.) R9 290X


That's a really bad idea.
The GPU Drivers don't play nice when they're both on the same system. It's one or the other, not both.
 

Xaymar

Active Member
There are multiple possible bottlenecks for why your FPS are significantly down:
  • The CPU can't keep up with the data throughput.
    AMDs FX series is one of the slowest CPU series in the market available. It severely under-performs in any workload, even a simple i5 is able to outperform it.
  • There's not enough PCI-E lanes to keep both GPUs running at full Speed.
    A really common mistake is to have two GPUs but not enough PCI-E lanes to keep both GPUs running at peak performance. Many systems only offer 16 or 24 PCI-E lanes, resulting in configurations that cut the available speed in half. A common configuration (until manually overriden) is 8+8 (16 lanes) and 16+8 (24 lanes), though some vendors also do 16+4 (20 total lanes) or 8+4 (12 total lanes).
    You can check what the AMD GPU is connected as by opening AMD Radeon Settings Crimson Edition, clicking System, then Hardware and reading the text that is shown under "Current Bus Settings" - for peak performance this should say x16.
There's also no point in having both GPUs just for the sake of encoding. Both GPUs offer a powerful HW encoder and you'd be better off just using the stronger GPU by itself.
 

Skullwar

New Member
There are multiple possible bottlenecks for why your FPS are significantly down:
  • The CPU can't keep up with the data throughput.
    AMDs FX series is one of the slowest CPU series in the market available. It severely under-performs in any workload, even a simple i5 is able to outperform it.
  • There's not enough PCI-E lanes to keep both GPUs running at full Speed.
    A really common mistake is to have two GPUs but not enough PCI-E lanes to keep both GPUs running at peak performance. Many systems only offer 16 or 24 PCI-E lanes, resulting in configurations that cut the available speed in half. A common configuration (until manually overriden) is 8+8 (16 lanes) and 16+8 (24 lanes), though some vendors also do 16+4 (20 total lanes) or 8+4 (12 total lanes).
    You can check what the AMD GPU is connected as by opening AMD Radeon Settings Crimson Edition, clicking System, then Hardware and reading the text that is shown under "Current Bus Settings" - for peak performance this should say x16.
There's also no point in having both GPUs just for the sake of encoding. Both GPUs offer a powerful HW encoder and you'd be better off just using the stronger GPU by itself.


Thanks! But It only loses FPS when I just the AMD encoder.
That's why I'm trying to figure out if OBS will even use the other GPU for encoding.
 

Xaymar

Active Member
Thanks! But It only loses FPS when I just the AMD encoder.

I just told you the reasons why it does lose FPS. You simply do not have a machine that can do multi-GPU data transfer without crippling its own performance. Cross-GPU encoding is a really heavy task, a single 1920x1080 60fps NV12 imagestream can easily use up any PCI-E bandwidth you have, resulting in drastically lower fps.
 

Skullwar

New Member
There's also no point in having both GPUs just for the sake of encoding. Both GPUs offer a powerful HW encoder and you'd be better off just using the stronger GPU by itself.

For the R9 other than trying to encode I use it for the other monitors.
 

Skullwar

New Member
There are multiple possible bottlenecks for why your FPS are significantly down:
  • There's not enough PCI-E lanes to keep both GPUs running at full Speed.
    A really common mistake is to have two GPUs but not enough PCI-E lanes to keep both GPUs running at peak performance. Many systems only offer 16 or 24 PCI-E lanes, resulting in configurations that cut the available speed in half. A common configuration (until manually overriden) is 8+8 (16 lanes) and 16+8 (24 lanes), though some vendors also do 16+4 (20 total lanes) or 8+4 (12 total lanes).
.

The Geforce is running on the x16 and the R9 is running on x4.
 

Xaymar

Active Member
As you have an AMD FX CPU, it is very likely that your board is only capable of PCI-E 2.0, which will give us a max rated speed of 4 GBit/s (actual speed is more around 2.3-2.5 GBit/s due to the CPU). At 1920x1080, NV12, 60fps you have an expected throughput of 1.5 GBit/s for both GPUs - the Nvidia GPU sends it to the CPU, the CPU sends it off to the AMD GPU. That is where your CPU usage is going, to just grabbing and sending frames. Any current generation (or last two Intel generations) can easily outperform your current system.

Now add to that the amount of data that needs to go through system memory onto the 2nd GPU for Monitors to work right and the fact that the game also requires GPU and CPU and there you have your reduced FPS explained too.

TL;DR: Your system is not equipped for multi-GPU, stick with one or the other not both.
 
Top