WEBVTT 00:00:00.160 --> 00:00:07.120 In front of me are 127 USB devices, the 00:00:04.880 --> 00:00:12.639 theoretical limit that is supported by a standard PC. But USB has [music] a dark 00:00:09.840 --> 00:00:17.760 secret. As it turns out, the real world limit is actually much, much lower. And 00:00:16.080 --> 00:00:24.640 the only way to find out what it is for sure is to just start plugging devices 00:00:20.560 --> 00:00:27.199 in, which oh well, I mean, I guess we 00:00:24.640 --> 00:00:31.679 could just read the white paper on the architecture of the spec, but 00:00:29.920 --> 00:00:36.000 that would be far less interesting for the people watching on YouTube. So 00:00:33.760 --> 00:00:40.239 instead, we're just going to start plugging things in and see what happens. 00:00:38.640 --> 00:00:46.000 What do you do once you run out of ports? I mean, hubs, obviously, but can 00:00:43.520 --> 00:00:50.480 we just keep plugging in hub after hub after hub until we hit it? What is the 00:00:48.480 --> 00:00:53.840 first factor that limits how many USB devices you can connect to your 00:00:51.680 --> 00:00:58.640 computer? Is one you know quite well, and that's the number of ports on the 00:00:55.920 --> 00:01:04.159 front and back of your PC. But what you might not know is that most computers 00:01:00.960 --> 00:01:06.159 only have a single USB host controller. 00:01:04.159 --> 00:01:11.119 And all of those ports are going to share not only that controller, but that 00:01:09.119 --> 00:01:18.159 controller's bandwidth. So when you have a USB 5 GB per second port, it's 5 Gbit 00:01:15.680 --> 00:01:22.880 per second shared with all the other ports on the controller. Now, 00:01:20.240 --> 00:01:29.360 fortunately, hitting a bandwidth limit is pretty uncommon. Most peripherals 00:01:25.920 --> 00:01:32.000 like mice or keyboards use a negligible 00:01:29.360 --> 00:01:37.280 amount of bandwidth. However, you can run into odd behavior if you have, say, 00:01:34.400 --> 00:01:42.479 for example, a video capture device or a webcam. This was really common with 00:01:39.840 --> 00:01:47.680 early generation VR headsets where the VR tracker sucked up so much bandwidth 00:01:45.200 --> 00:01:52.720 that users needed to install a second controller on an add-in card. Of course, 00:01:50.399 --> 00:01:56.880 our question today isn't how much bandwidth can we push through one of 00:01:54.159 --> 00:02:02.000 these controllers. [music] It's how many devices can we connect to one. So, let's 00:01:59.840 --> 00:02:08.160 move beyond the limits of our mere mortal rear IO ports. I summon the hub. 00:02:06.880 --> 00:02:16.000 I haven't even plugged the hub in yet, and I think we're already getting kind of weird behavior. None of these. Whoa, 00:02:12.720 --> 00:02:20.560 this mouse is crazy hot. Wait, 00:02:16.000 --> 00:02:23.280 heatedmouse.com. Oh, it's a feature. 00:02:20.560 --> 00:02:30.239 All right. Simple unpowered hub. 00:02:27.360 --> 00:02:35.840 Now a mouse. Hey, there it is. Logitech gaming mouse. Now another drive. Ah, but 00:02:33.040 --> 00:02:43.120 this is interesting. Every hub is actually two hubs. See that? We've got a 00:02:38.800 --> 00:02:44.720 USB 2 hub and a USB 3 hub. And depending 00:02:43.120 --> 00:02:48.640 on what kind of devices we plug in, they'll show up under either. Hubs like 00:02:46.720 --> 00:02:53.280 this one are an integral part of the various USB specifications. They handle 00:02:51.360 --> 00:02:57.599 all the communication between devices that are plugged into them and the host 00:02:55.760 --> 00:03:02.400 systems that they're plugged into, as well as handling bandwidth sharing. The 00:02:59.760 --> 00:03:06.800 hub will tell the system, hey, I'm a hub. And the system adds that hub's 00:03:04.800 --> 00:03:11.120 address to the path of any devices that are plugged in down the chain. When 00:03:09.120 --> 00:03:16.000 multiple hubs are used, multiple addresses are added to the path. So if 00:03:13.599 --> 00:03:21.519 hub A, for example, is plugged into port four of the host, hub B is plugged into 00:03:19.040 --> 00:03:27.040 port two of hub A, and then a mouse is plugged into port one of hub B, the 00:03:23.840 --> 00:03:28.800 address might read something like 0421, 00:03:27.040 --> 00:03:33.599 where zero is the address of the controller's root hub. Powered or 00:03:31.840 --> 00:03:38.799 unpowered, it doesn't change the addressing system. However, according to 00:03:36.239 --> 00:03:43.680 the USB spec, a hub that is powered entirely by the port that it's plugged 00:03:40.560 --> 00:03:45.977 into, like this one, cannot allow this 00:03:43.680 --> 00:03:51.200 sort of daisy chaining. According [music] to the spec, anyway, as we are 00:03:48.319 --> 00:04:00.080 about to see, however, that is not the case here, right? Look at this. But why 00:03:55.920 --> 00:04:02.319 though? Because unpowered hubs are liars 00:04:00.080 --> 00:04:07.760 sometimes. Actually, not just sometimes, most of the time. And if that shocks 00:04:04.480 --> 00:04:10.720 you, well, it shouldn't. Consider their 00:04:07.760 --> 00:04:16.239 predicament. According to the spec, only low power devices, so devices that draw 00:04:13.680 --> 00:04:21.120 less than 100 milliamps, are [music] supposed to be used on hubs that are 00:04:18.400 --> 00:04:27.199 powered by the port itself and not by an external power brick. So, if people buy 00:04:24.479 --> 00:04:31.840 a spec compliant unpowered hub, they're going to be in for a rude shock when 00:04:29.440 --> 00:04:38.720 many of their devices, I mean, even mice with too many RGB lights won't work for 00:04:35.360 --> 00:04:41.919 some unclear reason. So, as a result, 00:04:38.720 --> 00:04:43.840 manufacturers can either have mostly 00:04:41.919 --> 00:04:48.880 happy customers and with an [music] out ofspec product or they can have USB 00:04:46.639 --> 00:04:52.960 implement form certification. Well, average Joe customer doesn't care about 00:04:50.960 --> 00:04:55.759 USB if certification. They might not even know that they exist. 00:04:54.479 --> 00:05:04.000 Whose castle is this? They just want a hub that works with their devices, and it usually will. 00:05:01.280 --> 00:05:08.160 However, draw too much current and your USB controller will shut down the 00:05:05.919 --> 00:05:12.160 connection from the source. Huh. Hopefully before anything gets damaged. 00:05:10.720 --> 00:05:19.440 Should we try that? Why don't we plug the heated mouse into this thing? 00:05:15.919 --> 00:05:22.880 Okay, working now. But what happens when 00:05:19.440 --> 00:05:25.199 we turn our heat to high? Oh wow, this 00:05:22.880 --> 00:05:31.360 is still working somehow. [music] I NEED MORE POWER. HOW ABOUT THIS K95 keyboard? 00:05:29.039 --> 00:05:36.080 Really? How is this all still working? More 00:05:33.199 --> 00:05:41.440 brightness. That was max brightness. Let's plug into a USB 2 port. That'll do 00:05:39.840 --> 00:05:47.840 it. And 00:05:43.440 --> 00:05:48.960 oh, the heat on. Really? Were you 00:05:47.840 --> 00:05:55.199 expecting this to work? I mean, no, not really. But 00:05:52.240 --> 00:06:00.039 time for another RGB keyboard. Okay, come on. This will 00:06:04.960 --> 00:06:10.560 two full RGB keyboards and a heated mouse. Do we have any bigger unpowered 00:06:10.080 --> 00:06:15.919 hubs? No, the these are the two unpowered hubs I could find. Most of our stuff seems to 00:06:14.400 --> 00:06:21.680 just be powered. And it's plugged into a USB 2 port, which means that it's [music] pulling at most 2 and 1/2 watts, 00:06:19.840 --> 00:06:26.080 which is crazy that all of that stuff just works. Okay, 00:06:23.919 --> 00:06:31.520 you know what? Probably overdrawing. What I [music] suspect is that this 00:06:28.240 --> 00:06:33.680 motherboard is just like, 00:06:31.520 --> 00:06:37.520 I will deliver more than spec. Unbelievable. I can't believe they just 00:06:35.199 --> 00:06:40.720 allow more power draw so that things function properly. 00:06:40.209 --> 00:06:47.199 [sighs] This will do it. Heated mouse, RGB 00:06:43.520 --> 00:06:49.680 keyboard, and stream deck. No, it 00:06:47.199 --> 00:06:55.120 doesn't have the software. That should I want it to light up full brightness. Oh, 00:06:51.759 --> 00:06:57.360 wait. Hold on. USB device not 00:06:55.120 --> 00:07:03.520 recognized. Last USB device you connected has malfunctioned. Yes, we've 00:06:59.759 --> 00:07:07.120 overwhelmed it. Wow. What the devil is 00:07:03.520 --> 00:07:08.880 that? She real unhappy. I suspect if we 00:07:07.120 --> 00:07:11.880 plug this directly into the back of the PC 00:07:13.120 --> 00:07:19.039 it would show up just fine. Elgato 00:07:16.639 --> 00:07:24.080 Stream Deck XL. There it is. Everything working perfectly. But we take it back 00:07:22.000 --> 00:07:33.039 out of here and we plug it into our unpowered hub 00:07:26.319 --> 00:07:34.575 and boom. Problem. Yes. Suck. 00:07:33.039 --> 00:07:40.080 Okay. It doesn't matter. The point is [music] there's a solution to that. 00:07:37.280 --> 00:07:46.080 powered USB hubs like this one from Sabrin that does a whopping 00:07:42.639 --> 00:07:48.880 16 devices. Now, something funky about 00:07:46.080 --> 00:07:53.440 these is that they are power mandatory hubs. Some are power optional. Remember 00:07:51.199 --> 00:07:58.479 that first one that I had over here? It actually has a barrel jack, so it can 00:07:55.759 --> 00:08:05.039 operate as a powered hub. This one, on the other hand, is like, uh-uh, no can 00:08:01.759 --> 00:08:09.520 do. Where's my cable? 00:08:05.039 --> 00:08:11.199 Zip, zilt, nada. But plug in a 90 watt 00:08:09.520 --> 00:08:15.919 charger. And hey, there we go. Ah, this is 00:08:14.800 --> 00:08:21.520 interesting. We're going to talk about this later. All the different hubs that 00:08:18.400 --> 00:08:23.680 are present here. But first, 00:08:21.520 --> 00:08:28.160 let's see if we can get our stream deck and our heated mouse and our RGB 00:08:26.319 --> 00:08:34.880 keyboard running at the same time. We got to turn on those ports, of course. 00:08:31.840 --> 00:08:37.599 No problem. With these, I can greatly 00:08:34.880 --> 00:08:43.120 expand my USB connectivity. All I have to do is daisy chain my hubs together, 00:08:40.719 --> 00:08:50.560 which should give me pretty much unlimited hubbery. 00:08:47.279 --> 00:08:54.160 Uh, except for one small problem. Too 00:08:50.560 --> 00:08:56.240 many USB hubs. A hub will not function 00:08:54.160 --> 00:09:00.560 when it's connected more than five hubs away from the root port. But this is 00:08:58.399 --> 00:09:06.959 only three hubs. Remember when we noticed that each of these one hubs was 00:09:03.600 --> 00:09:11.440 identifying as five hubs in software 00:09:06.959 --> 00:09:15.680 sort of okay USB hub chips can have up 00:09:11.440 --> 00:09:19.040 to seven downstreamfacing ports or DFPs. 00:09:15.680 --> 00:09:21.519 Most hub chips have only four DFPs. So, 00:09:19.040 --> 00:09:26.720 a manufacturer looking to make a big tough USB bar that doubles as a 00:09:24.240 --> 00:09:31.360 self-defense weapon could achieve their desired number of ports by doing what 00:09:28.399 --> 00:09:34.320 anyone else would, by chaining them together. This particular model from 00:09:33.680 --> 00:09:40.640 Sabrant [music] has one main chip with four DFPs that 00:09:37.920 --> 00:09:46.560 each branch off into four more chips with four more [music] DFPs each. That 00:09:43.120 --> 00:09:51.600 gives us a total of 16 ports, each of 00:09:46.560 --> 00:09:53.839 which are two hubs deep. So if we put 00:09:51.600 --> 00:09:58.720 three of these together, that's [music] six hubs in a row. Of course, all of 00:09:56.399 --> 00:10:03.600 this hub into hub tom foolery was just an excuse for me to talk about hub depth 00:10:00.800 --> 00:10:09.920 limitations. The real way to plug in as many devices as we can is to plug each 00:10:06.880 --> 00:10:12.560 of our hubs into the back of our PC. 00:10:09.920 --> 00:10:18.079 Now, we're only two hubs deep on every one of these ports, meaning we can start 00:10:15.200 --> 00:10:23.040 loading things up. I could use a couple of extra hands here, boys. 00:10:20.959 --> 00:10:28.320 I'm actually going to turn these off just so that I can do this. 00:10:26.842 --> 00:10:31.920 [laughter] We're not going to be able to use USB thumb drives forever, though. 00:10:30.079 --> 00:10:35.200 Windows gets kind of fussy about how many drive letters it will assign. So, 00:10:33.600 --> 00:10:40.480 I'm just going to do one hub worth of these. We'll start bringing over mice. Yeah. 00:10:38.399 --> 00:10:44.800 Why don't we have a mouse hub, a USB thumb drive hub, and a keyboard hub? 00:10:42.720 --> 00:10:53.279 What do you guys think? Sound good? Yeah. We are up to 30 devices now. And I got 00:10:49.120 --> 00:10:54.720 to say, good old USB. You know, we kind 00:10:53.279 --> 00:11:00.720 of take it for granted. You know, you just use it every day and don't think about it. But it is shockingly robust. 00:10:59.120 --> 00:11:04.079 Are you guys um What are you guys doing with the keyboards over there? 00:11:02.240 --> 00:11:07.920 Uh we need to plug some in right now is what we need to do. All right. Hit me with some cables. 00:11:06.320 --> 00:11:12.240 Cable me. Plug these two in. Better believe it. We've made it to 48 00:11:10.320 --> 00:11:18.320 devices, all of which are showing up correctly. And while there is some weird 00:11:14.160 --> 00:11:20.800 behavior, uh I can't click sometimes, 00:11:18.320 --> 00:11:25.120 for example. Yep, that's uh Hold on. Maybe a different mouse will click. No. 00:11:22.560 --> 00:11:31.200 Um how about this? No. Nope. That doesn't work. But uh what 00:11:27.839 --> 00:11:34.000 about the Windows key? Oh. Uh control 00:11:31.200 --> 00:11:40.800 shift escape. Hello. Oh yeah, but could bring up task manager. So that's good. 00:11:36.079 --> 00:11:42.959 Alt F4. Anything, buddy? Shoot. Okay, 00:11:40.800 --> 00:11:48.640 let's go. Just one keyboard and one mouse for a 00:11:46.880 --> 00:11:52.079 sec here. Why was I able to click on that one thing and not a different 00:11:50.240 --> 00:12:03.279 thing? This is so weird. Okay. Yes, we're back. 00:11:58.800 --> 00:12:08.720 And come back all my pretties. Okay. 00:12:03.279 --> 00:12:10.639 Excellent. May I have another hub? 00:12:08.720 --> 00:12:13.440 There is a point to this. We're on a different screen now. And I'll show you 00:12:11.760 --> 00:12:19.880 why this is important. Let me just get everything lit back up here first. It's 00:12:15.600 --> 00:12:19.880 at 114 right now. 00:12:20.880 --> 00:12:27.320 We're at 172. 00:12:24.320 --> 00:12:27.320 Uh, 00:12:29.279 --> 00:12:37.360 this is not what I was expecting to happen, but we have a total of 234 end 00:12:35.279 --> 00:12:40.399 points. Um, Tanner. Yeah, 00:12:38.560 --> 00:12:46.079 that's not what we were expecting to happen, is it? 00:12:41.600 --> 00:12:48.800 Not at all. I haven't found so much as a 00:12:46.079 --> 00:12:55.040 data sheet for a USB root hub that can handle more than 128. [music] 00:12:50.639 --> 00:12:57.200 It's supposed to fail at 127. Well, 128. 00:12:55.040 --> 00:13:02.320 Um, it did not. 00:12:58.880 --> 00:13:05.360 Apparently, the AMD 00:13:02.320 --> 00:13:07.120 chipset is just very powerful when it 00:13:05.360 --> 00:13:10.120 comes to the amount of USB it can handle. 00:13:10.240 --> 00:13:15.600 More devices. Tanner, what is it supposed to do? 00:13:14.000 --> 00:13:19.760 Uh, it's supposed to tell you that it's out of resources. 00:13:17.279 --> 00:13:24.320 I see. And were you ever actually able to create that condition? tons of times. 00:13:23.360 --> 00:13:30.959 Cool. It became something I could do in less than five minutes on both my laptop and 00:13:29.120 --> 00:13:35.360 the system I was testing on. I see. Those are both Intelbased [music] 00:13:32.959 --> 00:13:38.720 systems and for some reason AMD just decided to go ham on the amount of USB 00:13:37.279 --> 00:13:43.519 they [music] can handle. Starting with AM4, but back then it was still limited 00:13:41.120 --> 00:13:50.160 to 128 and I expected it to be at least somewhere near 128 00:13:47.120 --> 00:13:53.959 still. But no, it What are we at right 00:13:50.160 --> 00:13:53.959 now? 304. 00:13:54.639 --> 00:14:01.920 Let's go. World new world record. 00:13:58.720 --> 00:14:04.720 Sum of hubs and devices is 101 right 00:14:01.920 --> 00:14:09.360 now. We are getting dangerously close to the goal we set out at the beginning of 00:14:06.399 --> 00:14:14.800 the video and we haven't even pulled out the USBator yet. I will be very 00:14:12.160 --> 00:14:22.639 disappointed if I don't need this. The theoretical limit of XHCI is like 8,000. 00:14:21.989 --> 00:14:27.199 [laughter] But how often do we reach theoretical 00:14:25.519 --> 00:14:31.440 limits for these things? I haven't been able to 00:14:29.839 --> 00:14:38.320 get anywhere near it without things breaking. And yet here we are with AMD 00:14:33.760 --> 00:14:40.320 just tanking it. Surely this final hub 00:14:38.320 --> 00:14:46.560 will be enough, he said, not really convinced. Oh, this 00:14:44.240 --> 00:14:52.480 video is completely off the rails now. There were rails. There was a script. 00:14:48.720 --> 00:14:54.399 There was a plan. Weeks of testing. And 00:14:52.480 --> 00:14:58.040 then we just happened to grab an AMD system. 106. 00:14:58.160 --> 00:15:04.959 Remember, cuz there's five hubs in here, right? Plus the one thing I replugged 00:15:01.945 --> 00:15:07.680 [music] back in. Uh, 00:15:04.959 --> 00:15:13.440 okay. I'm just going to start finding plugs and plugging them into things. 00:15:10.320 --> 00:15:18.680 Why, thank you, good sir. 00:15:13.440 --> 00:15:18.680 Holy 337 end points. 00:15:18.880 --> 00:15:26.399 Wait. Oh. Oh, we just lost a bunch. We're down to 270 end points all of a 00:15:24.800 --> 00:15:31.360 sudden. The keyboards are dead. Whoa. We are 00:15:28.560 --> 00:15:37.440 losing devices left and right here. We're 00:15:33.760 --> 00:15:40.079 Did we just completely 00:15:37.440 --> 00:15:45.839 Oh, wow. They're coming back. Okay. Wow. This is not what you want to see. 00:15:42.800 --> 00:15:47.920 Well, cool. At any rate, here's screen 00:15:45.839 --> 00:15:52.380 capture of the normal way that this happens that Tanner will get later. And 00:15:50.800 --> 00:15:59.440 this is also a thing that can happen [music] when you have too many endpoints. Allow me to explain. It's not 00:15:56.399 --> 00:16:01.550 a device limit or a power limit or a 00:15:59.440 --> 00:16:07.199 bandwidth limit. This is an endpoint [music] limit. An end point is a data 00:16:04.399 --> 00:16:11.279 pipe between the host and the device. And a device will typically have 00:16:08.959 --> 00:16:16.160 multiple end points for things like configuration, um, occasional small low 00:16:14.399 --> 00:16:21.040 latency data transfer, [music] non-timeritical large data transfer, and 00:16:19.199 --> 00:16:25.519 continuous data flow for things like microphones or cameras. Now, remember 00:16:23.839 --> 00:16:30.800 when I said that, well, they're all buried now, but these hubs were actually 00:16:28.320 --> 00:16:38.079 five hubs. Well, that was half true. They are five USB 3 hubs [music] 00:16:33.600 --> 00:16:40.959 and they are also five USB 2 hubs for a 00:16:38.079 --> 00:16:47.440 total of 10 hubs. Each hub [music] uses two endpoints for a total of 20. Now 00:16:44.320 --> 00:16:49.519 technically XHCI extended host control 00:16:47.440 --> 00:16:55.920 protocol supports up to [music] 31 endpoints per device which assuming a 00:16:52.959 --> 00:17:00.399 reasonable 127 device limit like we encountered in our testing [music] is 00:16:57.680 --> 00:17:04.000 nearly 4,000 end points. That's enough endpoints to fill up a tech sack from 00:17:02.160 --> 00:17:07.039 ltdstore.com. But you're not going to be able to 00:17:05.439 --> 00:17:12.480 actually hit that limit with modern hardware because controllers almost 00:17:09.280 --> 00:17:15.120 always have a limit [music] of 64 to 128 00:17:12.480 --> 00:17:19.679 endpoints, typically settling on around 96. 00:17:16.640 --> 00:17:22.319 Except that this one didn't. It had like 00:17:19.679 --> 00:17:28.720 over 300 or something. But that doesn't matter because we are still going to get 00:17:24.559 --> 00:17:31.919 to our goal of plugging in 128 devices 00:17:28.720 --> 00:17:34.400 with the USBator. 00:17:31.919 --> 00:17:38.799 And it should actually behave less flakier than this. Maybe. 00:17:37.120 --> 00:17:45.039 Don't make promises you can't keep. The one with all the USB drives in it is 00:17:42.240 --> 00:17:48.679 flipping hot. Like unhappy. 00:17:48.720 --> 00:17:55.200 Wow. Ow. You know, it kind of is a good 00:17:53.679 --> 00:18:01.280 representation of the difference in philosophy between Intel and AMD. Intel 00:17:58.080 --> 00:18:03.919 has a tendency to just say this is what 00:18:01.280 --> 00:18:07.600 we know we can support reasonably well and just no, you actually may not have 00:18:05.600 --> 00:18:12.400 any more than that. Whereas AMD tends to be kind of more yolo like I don't know, 00:18:10.799 --> 00:18:18.447 see what happens. We're not going to put a limit on it. What you are looking at 00:18:15.280 --> 00:18:19.840 here is an ASUS mining motherboard. Not 00:18:18.447 --> 00:18:27.760 [music] because we're doing any Bitcoin mining or anything like that, but because we want a whole bunch of PCIe by 00:18:24.720 --> 00:18:30.640 one slots plugged into a whole bunch of 00:18:27.760 --> 00:18:35.919 these little mining daughter boards that instead of being loaded up with graphics 00:18:32.400 --> 00:18:40.880 cards are loaded up with USB controller 00:18:35.919 --> 00:18:44.559 cards. In total, I believe we have 30 00:18:40.880 --> 00:18:47.360 total USB controllers, meaning that we 00:18:44.559 --> 00:18:54.480 are going to be nowhere near any kind of endpoint limit shenanigans to get to our 00:18:50.880 --> 00:18:56.640 127 devices. From the outside, the USB 00:18:54.480 --> 00:19:00.559 and is very similar to what we were just doing. We've got these Sabrin 16 port 00:18:58.880 --> 00:19:04.480 hubs, and we're going to plug them into ports in the back of our computer. But 00:19:02.559 --> 00:19:09.760 it's these ports that make this system different. StarTech sent over two 00:19:06.880 --> 00:19:14.400 different kinds of USB controller cards. These ones with seven plugs and these 00:19:12.160 --> 00:19:19.039 ones with four. [music] And believe it or not, the ones with four plugs are 00:19:16.960 --> 00:19:22.160 actually better than the ones with seven. And that's because, and if you've 00:19:20.880 --> 00:19:26.880 been paying close attention, you'll know why this matters. Four of these ports, 00:19:24.720 --> 00:19:31.200 namely the top ones, are running off of an integrated hub. Meaning that it would 00:19:29.039 --> 00:19:36.080 be much easier to hit an endpoint limit using these. So, for example, if you had 00:19:33.520 --> 00:19:41.280 a couple more multiport hubs and then one of these multi-dis adapter things, 00:19:39.440 --> 00:19:46.720 it would work in any of these bottom three, which are directly connected to 00:19:43.600 --> 00:19:48.640 the controller, but would cease to work 00:19:46.720 --> 00:19:54.640 if it was connected to one of the top four. That is not true of our four port 00:19:52.160 --> 00:19:58.640 cards. Each of these is running off of its own controller, meaning that the 00:19:56.480 --> 00:20:04.880 theoretical maximum number of endpoints going into just one of these cards would 00:20:00.960 --> 00:20:08.640 be 508 or something like that, assuming 00:20:04.880 --> 00:20:11.120 each of these can do 127 endpoints. What 00:20:08.640 --> 00:20:16.000 that means is that if all goes according to plan, it should be basically 00:20:13.360 --> 00:20:21.120 impossible for us to reach an endpoint limit on this system. I say we power the 00:20:18.880 --> 00:20:26.000 thing on. All right, because the first thing that we need to do is uh 00:20:23.600 --> 00:20:28.960 is verify which of these cards currently feels like working. Ah, 00:20:27.360 --> 00:20:32.240 it's not the card's fault. It's the risers, right? Mining stuff. Definitely [snorts] 00:20:31.600 --> 00:20:38.080 reliable. Oh, so reliable. This one has no lights. This one has no 00:20:35.360 --> 00:20:42.240 lights. That's okay. I can work with that. I regret taking the approach we 00:20:40.559 --> 00:20:45.760 did last time. Why? How many total drives did you say that 00:20:44.880 --> 00:20:51.120 you could handle? As many as there are letters in the alphabet. But really the problem is when 00:20:49.600 --> 00:20:55.440 a whole bunch of them connect at the same time, then Windows tries and give 00:20:53.039 --> 00:20:59.600 tries to give the drive letter to multiple drives at once. 00:20:56.799 --> 00:21:04.320 Sick. It is time to painstakingly plug in 127 USB devices. How are we doing 00:21:03.120 --> 00:21:10.640 here? What how are we doing for endpoints, boys? We're we're at 56 total peripherals. End 00:21:08.640 --> 00:21:13.360 points are going to be just based on the controller itself. So, we've got 00:21:12.080 --> 00:21:20.320 multiple controllers, but yeah, we're at 56. 56 and 122 standard hubs. 00:21:16.480 --> 00:21:23.440 Not bad. Let's do more. We are up to 86 00:21:20.320 --> 00:21:25.440 peripheral devices. The question is, are 00:21:23.440 --> 00:21:29.760 they still functioning at all? Let's do my caps lock test. 00:21:28.480 --> 00:21:37.760 So, you should be able to kind of see them going going nuts. Okay. What about 00:21:33.520 --> 00:21:40.799 the Windows key? Wow. 00:21:37.760 --> 00:21:42.720 Okay. With all these controllers, it's 00:21:40.799 --> 00:21:50.159 actually still kind of working. Can I Can I click on something? Yes. 00:21:46.640 --> 00:21:52.320 Very nice. MORE THUMB DRIVES. I AM uh 00:21:50.159 --> 00:21:58.799 I'm getting kind of nervous about the lean going on here. Like that is that is 00:21:55.280 --> 00:22:00.880 some pizza level almost. And there is a 00:21:58.799 --> 00:22:05.919 single strip of tape holding these on. It's good tape, but that's 16 ports 00:22:03.679 --> 00:22:12.799 worth of stress. We're at 100 devices right now. 100 devices. Let's go. I have to say my 00:22:09.360 --> 00:22:14.960 side much more organized. 00:22:12.799 --> 00:22:18.799 I did take the only rack though. Yeah. 00:22:16.640 --> 00:22:24.320 We have a mouse infestation. 104. 00:22:21.520 --> 00:22:29.679 Okay. Are any of these not lit up? Oh, that's that heated one. Yeah. 00:22:27.360 --> 00:22:33.360 Weirds me out, man. Oh crap. Something is depressed. 00:22:32.720 --> 00:22:39.919 Uh-oh. Oh, sorry. No, no, not that kind of depressed. Oh, 00:22:37.200 --> 00:22:42.880 are some of the ports not powered? Are some of them not powered on this side? 00:22:41.360 --> 00:22:46.480 Okay. No, they're definitely all powered away. Oh, okay. What are we up to now, 00:22:44.480 --> 00:22:52.640 Colin? Ah, 112. Oh, we're so close. 113. Come 00:22:50.880 --> 00:22:57.760 on. That didn't count. That also didn't 00:22:55.440 --> 00:23:04.240 count. Oh, we're down. We're down to 110. 00:22:59.280 --> 00:23:06.480 Okay. What about this one? Oh no. Oh no. 00:23:04.240 --> 00:23:11.440 Oh, I just saw keyboard lose power. I wonder if this is more of a driver 00:23:08.960 --> 00:23:17.039 level limit just trying to manage all of these flipping. What does our CPU usage 00:23:14.240 --> 00:23:22.200 look like? Look at my cursor now. Just hold on a gosh darn second 00:23:19.200 --> 00:23:22.200 here. 00:23:23.760 --> 00:23:31.120 Okay, it's not exactly a super powerful CPU. 00:23:28.000 --> 00:23:35.039 It's only a quad core, but 00:23:31.120 --> 00:23:38.000 we were pulling 60% when I opened this 00:23:35.039 --> 00:23:44.480 and it's sitting at 30 40% [music] now, just doing nothing. While I'm 00:23:41.360 --> 00:23:47.200 disappointed that we couldn't get to 127 00:23:44.480 --> 00:23:51.520 concurrent devices, we learned a lot along the way. And in fact, I have had 00:23:49.600 --> 00:23:55.280 multiple times in the past when I've run into issues that would have been caused 00:23:53.039 --> 00:24:00.080 by these kinds of topology limitations that just I didn't understand in the 00:23:58.080 --> 00:24:04.291 past [music] and now I will. So, the main things to take away here are that 00:24:02.240 --> 00:24:09.200 if you're using a hub, you're going to [music] want to connect that directly to 00:24:06.559 --> 00:24:14.159 the root controller. And if you're using an unpowered hub, hey, it might [music] 00:24:12.320 --> 00:24:18.080 be running out of spec. So, make sure you're only plugging in low power 00:24:15.600 --> 00:24:22.520 devices or get yourself a powered hub. We're down to 99, guys. 00:24:23.840 --> 00:24:28.880 I think she can't take it anymore. 00:24:27.039 --> 00:24:34.320 If you guys enjoyed this video, maybe check out the one where we oh connected 00:24:31.679 --> 00:24:38.799 as many PCIe risers as we could to see what would happen. You actually [music] 00:24:35.760 --> 00:24:38.799 ended up getting really