For Speed, Reliability and Security, Wi-Fi is Good. Ethernet is MUCH Better.

When we built our house in 1996 I took the opportunity to install all the “low-voltage” wiring myself. Before the insulation and sheetrock went up on the walls, I ran speaker wire for the living room surround sound and five other audio zones, additional phone cable for IR pickups in each zone and Cat5 Ethernet cabling everywhere I thought I might need it. Of course, now there’s wiring in the walls I’ll never use and I’ve had to run a couple of others to places my original plan didn’t include. Cloudy crystal ball aside, I’m glad I spent the money and made the effort. Especially on the Ethernet cabling. Wi-Fi technology has progressed geometrically over the past twenty years with theoretical speeds exceeding gigabit levels, but even the latest and greatest Wi-Fi gear can’t approach the real-world performance of a good, old copper wire.

So, why spend the time and effort to point this out? Because this concept has been lost on today’s PC consumers. Wi-Fi has gotten so much faster and so easy to set up that it’s good enough for most users. It has effectively replaced Ethernet as the default networking method. So much so that Apple no longer includes built-in Ethernet on any portable machine it sells and other manufacturers are following suit. Today’s super thin laptop designs can no longer accommodate Ethernet’s RJ-6 connector. Connecting any Mac portable to Ethernet requires purchase of a $30 Thunderbolt to Ethernet or USB to Ethernet adapter. 

I have the latest Apple Wi-Fi gear. My router is the current model AirPort Extreme and my MacBook Pro is a 2014 model. When connected via Wi-Fi under ideal conditions (~20 ft. apart with line-of-sight) my MBP reports a 5GHz 1300+ Mb/sec. (megabits (little “b”) per second) connection. * When you do the math, that connection should be able to transfer data at over 160 MB/sec (megabytes (big “B”) per second), but that just doesn’t happen in the real world. When I try copying a 4 gig movie (.mp4) file I typically max out at 65 – 70 MB per second (or 560 Mb/sec.). If I move my laptop somewhere with a lesser signal (basically anywhere else) the speed drops dramatically. Just moving to the next room cuts the speed in half. By contrast, the same movie copies at 115 – 120 MB/sec. when I use my Ethernet adapter. So, why is copying files over Ethernet twice as fast when the connection is reportedly 30% slower than the a/c Wi-Fi? When I noticed this discrepancy I decided to do some more precise testing using the iperf command-line tool. (Read my post about iperf here.) Briefly, iperf is a free tool used to test real-world network speed. It eliminates variability caused by file systems and network protocols. After all was said and done, iperf reported similar speeds (in Megabits per second) to my movie copying test…

So, why the big difference? And why is the variability within the Wi-Fi results so much greater? I dunno. Maybe it has something to do with the WPA2 encryption required by Wi-Fi. Maybe my daughter’s fancy hair dryer interferes with the 5 GHz band. Maybe the NSA is conducting a “man in the middle” interception of my signal. Who knows? Does it matter? Maybe. It depends on what you’re doing. If you’re surfing or downloading things from the Internet you probably won’t notice. Well, you might notice if you have a gigabit fiber broadband connection, but most of us peons will never notice. If, however, you’re backing up to a network share or moving large chunks of data like media files from one computer to another you’ll definitely appreciate the speed and reliability of a good copper connection. In short: 20 megs, no difference. 20 gigs, BIG difference.

The biggest problem with Wi-Fi is signal variability. I conducted this test under the best Wi-Fi conditions I could muster. A 1300 Mb/sec. connection isn’t likely to be the norm. I’ve been a Cisco certified network engineer for over 20 years and I’ve come to believe Wi-Fi connectivity has more to do with black magic than science. You’ve been there, right? Have trouble connecting when you’re on your sofa 10 feet from your router but two rooms away in the bedroom everything works great? Or, two people sitting at the dining room table with their laptops; one person’s connection drops and the other’s is just fine? I’m kidding about the black magic of course, but there are so many variables that can affect Wi-Fi connectivity it can be next to impossible to troubleshoot and often not worth the effort when moving ten feet in any direction can fix the problem. Well, I believe the best fix for Wi-Fi is not to use it whenever possible. With Ethernet you never worry about security, connectivity or speed issues. I thank my lucky stars for all the copper I installed when we built our home.

I’d like to brag about my great foresight being the reason I installed all the Cat5 cabling 20 years ago, but the truth is, Wi-Fi was nascent technology in 1996. The 802.11 standard wasn’t even released until 1997 and then it only specified 2 megabits per second. Conversely, 100 megabit Ethernet was becoming commonplace with lots of consumer-grade hardware available at reasonable prices.

Today, gigabit Ethernet hardware is downright cheap. The biggest expense by far is the cabling and uncomplicated cable runs through inside walls (walls without insulation) and attics are truly do-it-yourself easy with tools costing less than $20. 8-port gigabit switches are readily available for less than $30 at Amazon, Monoprice and Best Buy and they are truly “plug-n-play” easy to set up. Building a three or four leg home network is easily a $200 weekend project.

These days a low-end computer has 250+ gigs of storage. It’s common for a household to have a couple of machines. My household is atypical with seven, but I have a disease (according to my wife). Backing up all that data over Wi-Fi is problematic at best. I use Time Machine on all my Macs and I back them up to a 4 TB USB drive attached to my AirPort Extreme. The two Windows machines are backed up to a Linux box with a 4 TB RAID. The Linux machine also hosts all my media. Pictures, music and movies total over 700 gigs. It’s a central repository that serves our three AppleTVs and my daughter’s Xbox. All this happens over my home gigabit network. Even my AppleTVs are plugged into the hard wire and I never have any trouble streaming multiple HD movies simultaneously. All the while my backups run without problems and I can move large files around at over 100 MB/sec. Try that over Wi-Fi and either something is going to fail or everything will happen at a snail’s pace. I’ve set up other people’s home network using Wi-Fi only and seen the problems first-hand. On one occasion I had to turn off Time Machine on a neighbor’s iMac so the AppleTV wouldn’t stutter while trying to stream a movie from the same machine. Time Machine was backing up to his Time Capsule over his a/c Wi-Fi that reported a 600 Mb/sec. connection. That shouldn’t have caused a problem, but whenever Time Machine ran, the streaming movie would hiccup. Two weeks later we ran Cat6 drops from the Time Capsule to his office and entertainment center. We also added a $20 5-port gigabit switch in the office so he could connect his MacBook also. Problem solved. Actually, it wasn’t necessary to run Cat6 cable to the AppleTV. As soon as we connected the iMac to the router we were able to backup the Mac while streaming a high definition movie to the AppleTV over Wi-Fi. Obviously, it was the iMac’s Wi-Fi connection that was being strained.

The point to all this is: For speed, reliability and security, Ethernet is just better than Wi-Fi. Period. Granted, Wi-Fi is very convenient, but you run Ethernet cabling once and you’re done. It really makes sense for desktop machines and home offices where you use your portable frequently and anyone can do it in just two or three hours. If you want your backups to happen faster, movies to stream smoother and data to copy more quickly from one device to another, copper is a better network medium than air.

*You can check your Mac’s Wi-Fi connection speed by <option> clicking the Wi-Fi icon in the menu bar.