Hi vMix folks,

I'm trialing the vMix software for my broadcasting purposes. We have worked with Wirecast at times, and that is a bit relevant in my question here.

I ran vMix recently and while it worked rather well the performance and CPU usage was not quite what I was anticipating.

For the production system I am using an AMD A8-6600K, which has an AMD Radeon 8570D GPU.

We previously have used a Core 2 Quad (I forget the exact model, I think it may have been a Q8400).

Now with Wirecast with the Core 2 Quad system we were able to do 1270x720 at 30fps at upwards of 2500kbps broadcasts very easily. We also were using a much less powerful GPU to accelerate the process. This resulted in 20-40% CPU utilization, and no visible frame loss.

Comparatively with the new hardware and using vMix we are getting much more CPU usage and more frequent frame loss.

Now, I may be doing this incorrectly, so is there any way I can improve my situation?

We're using Windows 7 64bit Pro. And the core content we care about is streaming 3d content (as in gaming) from another system to the production system.

I will gladly clarify where needed.

Hi,

FMLE tends to use a lot of CPU usage for image scaling, to fix this:

1. In vMix Settings go to External Output and set the Output Size to 1280x720 (or whatever the largest encode size is under the Streaming Window) under Virtual Capture
2. Restart vMix and try streaming again.

On our test systems the CPU usage of FMLE is reduced from 55-60% to 25% this way.

Regards,

Martin
vMix

Martin, that is interesting. Do you also see this reduction when FMLE is set to stream out at a lower resolution but the input is set as above?

I'm pretty sure I have 1280x720 set at all the relevant spots, but just in-case, where should I be looking for all the spots?

Also, for the sake of semantics, 1280x720 is HD ;o

There are two fields for Output size, one for "vMix Video Device" and one for "External Recorder"

I only have vMix Video Device checked. What is External Renderer for and should I use it with/instead?

According to passmark (a site I use to reference CPU and other benchmarks) the A8-6600K has a CPU performance score of 4814, which is measurably over a q8400 of 3246 which is similar to what we were using previously. However the i5-3570k has a score of 7116, so that may explain why I'm getting more percentile use.

Hopefully we can get this figured out, because I'm really loving other aspects of vMix so far. I just figured out the stinger feature, and am trying to figure out the editable lower-thirds.

Any other thoughts? D:

Thanks for your help so far :)

I also will look at updating directx with dxwebsetup as FMLE may use DirectX for acceleration (or that's vMix, I forget).