Warning! The following post offers expert input on a technical topic that is often debated. If interested in the topic, please continue reading.
As the use of video in our daily consumption increases, the question of whether or not it’s worth upgrading i5 to i7 for video encoding is being asked more frequently. Before we go any further, let’s just take a look at the basic difference between the Core i5 and Core i7.
- A quad-core i5 processor easily maintains four simultaneous “threads.” Software then uses these “threads” to manage multiple tasks at once, rather than queuing everything up for sequential execution.
- Core i7 processors use “hyper-threading” to reach above and beyond the number of cores they have. Therefore, a Core i7 processor with four cores can handle eight threads simultaneously.
The benefit of hyper-threading comes into play when video encoding is needed during an active video conference call. In a video conference (VC) call, all applications control the resolution they transmit. What this means is that even though the connected cameras may provide a high resolution, the application ultimately selects what they transmit. VC applications may drop the resolution because of network congestion.
The encoded rate can also be a function of perceived platform capability and maximum display resolution for the destination client. Current VC apps allow a maximum resolution of 1080p (with a few exceptions, such as Vidyo).
We ran a Skype for Business call between an i5 and i7 to test the remote video quality. To isolate network-dependent rate control, both computers were connected to the same network. The computer with an i7 processor was able to encode the video at a higher bitrate, resulting in a better quality (SNR) to the far side. The i5 platform outgoing bitrate, on the other hand, was lower, which correspondingly caused a dip in the remote video quality.
In Figure 1 and 2 below we show i7 and i5 sending and receiving bitrates with corresponding received video screenshots, respectively. The core i7 send bitrate is 3.3 Mbps higher than the core i5 send rate of 2.9 Mbps. The receive bitrate is similarly reduced at the core i7 viz-a-viz the core i5.
Fig 1: Core i7 send and receive rates with received video screenshot.
Figure 2: Core i5 send and receive rates with received video quality.
With these images, you can see that the video originating from the core i5 and viewed at the remote end has a lower SNR quality – even at the same resolution.
In conclusion, it is clearly beneficial to use a computer with higher processing power for better media quality imposed by the individual VC application rate adaptation constraints.
About the Author:
Javed has over 18 years of IT experience in Sales, BD and Solutions Architect roles in managing and running teams to drive customer success. He has held leadership positions in various roles at Cisco Systems leading Solutions Architects, Sales and Business Development teams. He continued in similar roles at Microsoft focusing on MS Lync sales and deployments at Fortune 100 customers before joining Altia Systems. Javed has deep understanding Collaboration and Video Solutions and has been a speaker at various Industry forums such as TechReady, TechEd, Cisco Live nationally and internationally. He holds a BS in Engineering and MS from Univ. of Colorado Boulder and holds CCIE/MCP certifications.