The Powerful System: PCs, Capture Cards, and Software Mixers for HD Capture and Streaming
By Jim Bask
By Jan Ozer from Streaming Media
Benchmarking PCs, Capture Cards, and Software Mixers for HD Capture and Streaming
To determine how powerful a system it takes to produce and deliver live event streams, we tested a range of computers (old and new), capture devices, and multiple live streaming software programs, streaming to one or more streaming services, recording archive/ISO files in various formats, and measuring CPU utilization. Read on for the results.
When you’re producing a live event with a self-built, computer-based system, your focus narrows to a single relevant question: Is the system powerful enough to produce the streams required for the event?
To help find out, we assembled a range of computers (old and new), obtained several capture devices, and downloaded multiple live streaming software programs. Then we ran multiple tests, streaming to one or more streaming services, recording archive/ISO files in various formats, and measuring CPU utilization. On the Windows-based systems, we captured the results in Performance Manager and annotated the output to produce graphics such as those shown in Figure 1. On the Mac, we simply recorded CPU utilization numbers during the tests.
Before discussing the results, let’s touch on testing procedure. First, to normalize the results, I used the same high-motion, high-detail AVCHD clip for all tests. Each time, I started the streaming and/or recording activity, triggered the recorded video, let it play through, and then stopped recording/streaming. Then I changed the configuration and started again. To add a touch of complexity, I added a logo overlay to all videos.
I’ll detail each computer system and capture device used when reviewing the test results. For the mixing software, I used a prerelease version of Telestream Wirecast 7.1. I was glad I did, since CPU utilization was down significantly from version 7.0, which was way down from version 6.0. I tested vMix version 17.0.0.107 and version 0.15.4 of Open Broadcaster Software (OBS).
Let’s start with notebook testing.
Notebook Testing
I ran the first tests on an HP ZBook Studio G3 Mobile Workstation with a 2.8GHz Xeon quad-core (eight with Hyper-Threading Technology [HTT]) E3-1505M CPU with 32GB of RAM running Windows 10. The first capture device was a USB 3-based Epiphan AV.io 4K video grabber.
Figure 1 (below) details the results of tests run with Wirecast version 7.1, though tests varied slightly with the capabilities of the software mixer. I started with a 720p/2.25Mbps stream to Facebook Live, and then added a 1080p/8Mbps archive encoded with x264, which boosted CPU utilization to more than 55%. By way of comparison, with Wirecast version 7.0.1, CPU utilization for x264 was more than 70%. Test three was Facebook Live plus an archive encoded with the more efficient Intel Quick Sync Video codec.
Figure 1. CPU utilization for Telestream Wirecast on a 2.8GHz HP ZBook with an Epiphan AV.io 4K video grabber [Continue Reading…]