CPU usage on Ethernet vs wifi

[mk313]

I've been a Mac guy for many years and everything 'just works' (usually). With COVID, I am now using my work PC at home. While it's going fine, I'm occasionally having issues on Webex meetings. Some audio drops, etc. I'm just not a 'tech guy' so I'm doing my best to try to figure this out.

I've asked a few questions about it on here & have my setup tweaked so it's about as good as can be. You guys helped me diagnose an issue with my wifi dropping to g speeds from ac, and that is now working correctly.

After fixing everything else, I've noticed (through monitoring Task Manager) that the limiting factor on my webex meetings seems to be my processor (A Lenovo Thinkpad T460). If I have several tabs open in my web browser when I use Webex, it can spike to 100% CPU usage. If I close my web browser, it usually drops down quite a bit. However, there are times that I need to present using a web browser, so I'm still trying to tweak my settings to use as little CPU as possible. I close out of every app that I'm not going to need for the call. My question is this: Is there any difference in CPU usage when using Wifi (802.11ac) vs ethernet? I've tried googling it, but I can't get a solid answer. I've tried it both ways on calls & during my daily usage and I don't notice a difference in any metrics (internet speed, ping, cpu usage, etc), but each call is slightly different so I can't tell for sure.

If there is no CPU usage benefit, Wifi is a lot easier to use as I don't have to run a cable, but if it takes any strain off the processor, I would be willing to plug into ethernet before calls.

Sorry if this is a dumb question, but I just can't seem to find an answer (maybe because it's an obvious answer).

 

[Erehy Dobon]

My guess is that your web conferencing issues have little to do with CPU usage but more to do with network performance.

The devices in today's home network environment put an enormous load on wireless networks which is why new wireless technologies (both WiFi as well as cellular data) emphasize features that help alleviate some of the wireless network traffic congestion.

Wireless network performance is affected by factors within your control (e.g., the number of devices connected to the network) as well as factors outside your direct control (e.g., interference by things like fluorescent lighting, microwave ovens, architectural barriers).

For this reason I try to use wired networking (Ethernet) as much as possible at home. This isn't exclusively for computers but also extends to other devices that have Ethernet jacks (an ancient AppleTV, Blu-ray player, even a Raspberry Pi 4).

If you have a WiFi-only device and aren't actively using it, you should consider shutting off WiFi on that device.

For sure, my geriatric iPod touch 5th generation can suck up as much network bandwidth as most other devices in my household despite its wimpy underclocked CPU. Same with my Raspberry Pi 4. I don't know what CPU is in my Roku Streaming Stick but it certainly isn't anything powerful.

 

[mk313]

Thanks for the reply. I’ll start using Ethernet and see if that helps. The weird thing, for me, is that if I use the webex app on my phone or iPad, I don't experience the same issues, but on the computer I do.

 

[tootyfrooty]

The iPad might be working on the 5GHz network which can transfer more data.

 

[2984839]

There should be no appreciable difference in CPU utilization, though ethernet is nearly always more reliable and faster than wifi for many other reasons.

In theory, your instinct is correct that wifi would consume more CPU time due to the necessity of encrypting and decrypting data. In much older chipsets and in CPUs that did not have AES hardware acceleration this may have been noticeable. However, nowadays the crypto heavy lifting is offloaded to specialized hardware within the wifi card and CPU so the impact is negligible.

 

[mk313]

There should be no appreciable difference in CPU utilization, though ethernet is nearly always more reliable and faster than wifi for many other reasons.

In theory, your instinct is correct that wifi would consume more CPU time due to the necessity of encrypting and decrypting data. In much older chipsets and in CPUs that did not have AES hardware acceleration this may have been noticeable. However, nowadays the crypto heavy lifting is offloaded to specialized hardware within the wifi card and CPU so the impact is negligible.

Thanks for that detailed explanation. I appreciate it & it makes total sense

 

[tootyfrooty]

Referring to the iPad may be quicker on wireless if it's on a 5Hz network, I don't think the CPU will have much to do with the issue. Obviously depends if you have a dual band router. (2.4Ghz & 5Ghz) just trying to think why your iPad does not have the same issues that your laptop has.