1 00:00:00,200 --> 00:00:04,680 Snake oil that only exists to take your money seems to be everywhere in the tech world 2 00:00:04,680 --> 00:00:10,840 from $1,000 HDMI cables to heat sinks for your hard drives, I mean, come on. 3 00:00:10,840 --> 00:00:16,600 And our Wi-Fi equipment is often no exception as manufacturers keep finding ways to make our routers 4 00:00:16,600 --> 00:00:20,920 and access points seem more powerful than they actually are. 5 00:00:20,920 --> 00:00:24,480 With one of the biggest culprits being how they've implemented a technology 6 00:00:24,480 --> 00:00:28,100 called multi-user, multi-input, multi-output, 7 00:00:28,100 --> 00:00:32,100 or MU MIMO, Mu MIMO. 8 00:00:32,100 --> 00:00:36,940 So what exactly is it supposed to do and why does it suck? 9 00:00:36,940 --> 00:00:40,460 To answer, we had a conversation with our good friend Joel Crane 10 00:00:40,460 --> 00:00:43,660 and we'd like to thank him for his input. Thanks Joel, love you. 11 00:00:43,660 --> 00:00:47,740 Now to understand this, we're gonna have to go all the way back to the early days of Wi-Fi 12 00:00:47,740 --> 00:00:52,460 where our routers and gadgets each had just one antenna on them. 13 00:00:52,460 --> 00:00:56,140 They're basically just rocks. So let's say your router sent out a signal. 14 00:00:56,140 --> 00:01:01,180 To do this, the same signal blasted outwards in many directions and because of this, 15 00:01:01,180 --> 00:01:06,620 the different waves carrying this same signal would bounce around the room and arrive at your laptop 16 00:01:06,620 --> 00:01:10,000 or Nintendo DS or whatever at different times. 17 00:01:10,000 --> 00:01:15,100 Kind of like when you hear an echo in a large warehouse like this one. 18 00:01:15,100 --> 00:01:19,500 Now these signals arriving at different times caused undesirable interference. 19 00:01:19,500 --> 00:01:24,460 So a solution was introduced with the 802.11N standard in 2009 20 00:01:24,460 --> 00:01:27,860 called multi-input multi-output or MIMO. 21 00:01:27,860 --> 00:01:32,020 We've heard of that before. The simplest way to think about it is that both the client and the router 22 00:01:32,020 --> 00:01:35,860 would each have two antennas and two radios. 23 00:01:35,860 --> 00:01:39,580 This would allow the client to recombine these waves that arrived at different times 24 00:01:39,580 --> 00:01:43,820 into one much cleaner wave for better range and reliability. 25 00:01:43,820 --> 00:01:48,660 A solution called Maximal Radio Combining or MRC. 26 00:01:48,660 --> 00:01:53,220 Additionally, the multiple radios also meant that the router could also put different data 27 00:01:53,260 --> 00:01:56,460 on each stream to transmit information more quickly 28 00:01:56,460 --> 00:01:59,860 in a technique called Spatial Multiplexing. 29 00:01:59,860 --> 00:02:02,860 Sounds like a wrestling move. For a two radio access point, 30 00:02:02,860 --> 00:02:06,020 you could pick either MRC or Spatial Multiplexing 31 00:02:06,020 --> 00:02:09,380 depending on whether you needed to prioritize speed or range. 32 00:02:09,380 --> 00:02:14,420 However, if you had three antennas, you could actually use both at the same time 33 00:02:14,420 --> 00:02:18,820 using two antennas for MRC and a third for Spatial Multiplexing 34 00:02:18,820 --> 00:02:22,060 or all three for one technique or the other 35 00:02:22,100 --> 00:02:26,780 depending on your needs. It was so great. Now all this actually worked pretty well 36 00:02:26,780 --> 00:02:30,300 and resulted in significant speed and reliability improvements. 37 00:02:30,300 --> 00:02:35,500 However, the powers that be asked, hey, what if we use these different antennas 38 00:02:35,500 --> 00:02:39,300 to talk to different devices all at the same time? 39 00:02:40,900 --> 00:02:44,580 With that, multi-user or MU MIMO was born. 40 00:02:44,580 --> 00:02:48,340 But unlike standard MIMO, also called single user MIMO, 41 00:02:48,340 --> 00:02:52,140 MU MIMO simply does not work as advertised. 42 00:02:52,140 --> 00:02:57,620 Let me explain. The stated advantage of MU MIMO is that the messages being sent out from the router 43 00:02:57,620 --> 00:03:03,220 will arrive at all your devices at the same time, which is theoretically faster than waiting around 44 00:03:03,220 --> 00:03:07,700 for the router to talk to one device at a time, which is how traditional Wi-Fi works. 45 00:03:07,700 --> 00:03:10,940 However, for the messages to arrive at the same time, 46 00:03:10,940 --> 00:03:16,540 they need to be the same size. Something that very, very rarely happens 47 00:03:16,540 --> 00:03:20,140 since the different devices on your network are asking for different data, 48 00:03:20,140 --> 00:03:25,180 meaning that one device is going to be waiting to finish receiving a message after the others are complete, 49 00:03:25,180 --> 00:03:29,780 largely nullifying any advantage. Now on top of that, making the router deal 50 00:03:29,780 --> 00:03:34,900 with timing signals to all those different devices at once creates management overhead, 51 00:03:34,900 --> 00:03:38,340 adding latency and further cutting into any time savings. 52 00:03:38,340 --> 00:03:42,380 So the issue is while MU MIMO technology does work, 53 00:03:42,380 --> 00:03:46,900 technically, you're simply not going to see any real world advantage from it. 54 00:03:46,900 --> 00:03:52,180 In fact, many common clients don't even bother supporting MU MIMO, including many higher end ones. 55 00:03:52,180 --> 00:03:56,580 So the bottom line is this, don't prioritize MU MIMO support 56 00:03:56,580 --> 00:04:01,060 when buying your next router. You're better off looking for things that actually matter, 57 00:04:01,060 --> 00:04:05,300 build quality, customizable settings, and an aesthetic that makes your living room 58 00:04:05,300 --> 00:04:09,500 look like an evil layer so that you can impress your friends at your next house party. 59 00:04:10,620 --> 00:04:14,660 If you want them to be scared, I guess. All right, thanks for watching, guys. 60 00:04:14,660 --> 00:04:18,860 If you liked the video, disliked the video, do a neutral like. 61 00:04:18,860 --> 00:04:21,900 If the thumb, neutral thumb, is that a thing? 62 00:04:21,900 --> 00:04:27,820 Check out our other videos, comment below with video suggestions, and don't forget to subscribe to Tech Quicky 63 00:04:27,820 --> 00:04:29,820 and follow Tech Quicky.