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Hey there, welcome to Streamer’s Haven! Or welcome back if you are a regular here, I suppose. Now, I wanted to include this information in the recent post that I did about whether or not the Stream Deck Mobile app was free, but I felt that the article was getting a bit long. Additionally, having a separate article allows me to focus on the benefits and drawbacks of using multiple stream decks, so I decided to separate it into its own thing.
With that out of the way, let’s get into it, shall we?
I’ll be quick about it. You and I both know you are here for one thing, and the answer is Yes. You can use as many stream decks as you have available USB ports. The software is able to differentiate between multiple stream decks in use, and you can switch between them when assigning functions. This video by TominationTime does a fantastic job showing the software as it would be when they are both connected.
However, I implore you to keep reading so you can learn about the potential difficulties you may run into.
Using multiple Stream Decks: Possible, but…
Live streamers tend to utilize a large number of USB devices, and that amount is only going up as more innovations like the Stream Deck are created. To start, you have the two essential devices for any modern PC – The Mouse and Keyboard. Unless you are utilizing the ancient PS/2 interface, that means two USB ports are reserved for these devices and are non-negotiable.
Unless you are a keyboard shortcut wizard, of course.
Then you have a USB charging cable for your Phone / other devices. This one is mostly optional, but the inconvenience of going to the back of your PC to unplug it is a strong enough deterrent to consider it essential. Of course, If you have a keyboard like the Logitech G Pro, and your devices use Micro-USB, this one can be marked off.
In all, you have two, maybe three devices that are more or less standard for any PC user.
Live Streamer focused devices
Here is where a live streamer differs from a gamer. The next “Mostly essential” device is a Webcam, and this device is extremely bandwidth-hungry, especially if you get a 4k Webcam. Some streamers even utilize multiple webcams for several perspectives to switch to on stream. For this, we will represent the number of webcams as a multiplier of ‘x’ in the formula below.
Next, you obviously intend to use multiple Stream Decks already, so there is one for that, again with a multiplier of ‘y’ this time.
Following that, you have your microphone, which is essential for a live streamer. If you use a USB mic like the AT2020 or even an XLR mic that goes into an audio interface or mixer, you are reserving an additional USB port for that device. Mixers and Audio interfaces are also very high bandwidth devices, so keep that in mind for later.
As for the headphones, some may go into the green audio jack in the back of your pc, while other, higher quality ones may use another USB connection. There are even some that will only connect into a 1/4″ jack that is used typically in audio interfaces and musical equipment. Still, there is a possibility of yours using a USB connection, like the Logitech G933 headset.
Finally, you have a budget-class USB-powered light that most streamers will utilize to act as their key lights. While this device has zero bandwidth needs, it does occupy a physical port.
So, in total that is:
- 2 (+1 optional) + 1(x) + 1(y) + 1(maybe 2), + 1/2 = 6 ports
Considerations to make
At the minimum, you are talking 6 ports consumed, which is basically the limit on most motherboards. Budget class boards typically ship with 6 ports. With that said, there are additional headers on the board you can utilize on pretty much every board to gain access to 2-4 additional USB 2.0 ports. Most also come with a 20 pin USB 3.0 header, for an additional two USB 3.0 ports. Unfortunately, they require that you purchase additional hardware to install on the back of your expansion slots, or a 5.25 / 3.5-inch front panel bay. That is, of course, unless your PC case comes equipped with the extra USB ports built-in. Mine did; though I did end up breaking them…
Pro-tip, don’t trip over your cable attached to a USB port on your pc. It will likely damage the port. Also, it will probably ruin any Joysticks you have connected to it too. It’s a long story, and let’s just blame the chair that I rolled over the wire of my joystick with, then proceeded to get up from my chair.
Then there external HDDs/SSDs. These are the real bandwidth hogs of all of the possible devices, especially if that SSD enclosure is using an NVME drive. I listed these last, as I don’t really consider them to be essential. I prefer my drives to be internal for my streaming/editing rig, as I have no reason to move them around.
What about USB hubs?
You certainly could utilize a USB hub (This one is a USB type-c to 2x USB 3.0 type A and a bunch of other connections) that will split a port or two into several. However, through the utilization of multiple high-bandwidth devices like webcams, HDD’s/SSD’s, and audio interfaces or mixers, you become increasingly susceptible to overwhelming the USB bus. The resulting symptoms can be anywhere from pretty annoying, to hugely detrimental to a live streamer.
No one device is capable of overwhelming the bus by itself, but it is the combination of multiple high-bandwidth devices that things start to change.
With that said, I’d avoid putting your stream deck on a USB hub unless you have no other choice. Not all hubs are created equal, and you may experience issues with it through a hub, though this is merely conjecture formed from my experience using my C920 webcam on the hub.
What is a USB Bus?
The use of the word “Bus” to describe this is actually pretty accurate. Think of it as a highway with people inside of a bus. These people need to get to work on time, So they all opt to get on a bus.
Rather than people, the USB bus carries data. This is probably a gross over-simplification, but you don’t really need to know the technical aspects as a live streamer.
What happens when you exceed the USB bus bandwidth?
|Symptoms of USB Bus saturation||Severity|
|Webcams can suddenly stop working||Major (for a streamer)|
|Mouse and keyboard may intermittently cut out||Major|
|The system may experience a blue screen||Severe|
|Applications that rely on USB may not work properly||Minor|
|OBS Studio can suddenly drop a lot of frames||Major|
If you have several attached devices to a single bus lane, that creates a lot of data to be transmitted to and from the CPU (Central Processing Unit). From this, the data lanes can become clogged, bottlenecked by the width of the traffic band (Aka, Bandwidth). The result of which can have many detrimental effects on the system as a whole. Expected data never arrives, resulting in packet loss, Things literally stop until that data arrives, resulting in a loss of processing efficiency and speed, and many many other issues.
There are a wide variety of symptoms that can occur when you exceed that USB bus limit. The first, and most comically, is that Windows will yell at you, saying that a USB Bus is over-saturated, or something along those lines. I forget what the exact message was, it has been a while since I saw it last when I used two 1080p webcams on the same bus as my audio interface and an external SSD enclosure.
What can be done to fix USB Bus saturation?
Luckily, this issue can usually be fixed by simply changing around the USB plugs into different ports to balance the load across multiple USB bus lanes. However, there are rare cases where this may not be an option. For example, when a live streamer opts to use 3+ webcams.
If you fall into this category, and are experiencing issues even after swapping around your ports multiple times, you have three options remaining:
Buy a PCI-E-to-USB expansion card, look into a second, dedicated streaming PC, or reduce the number of USB devices you are using.
Luckily, a Stream deck isn’t a very high bandwidth device; though it is higher than a standard USB keypad. Using multiple Stream decks on your setup shouldn’t be a problem if you are willing to buy one of the expansion bays mentioned, or one of the PCI-E-to-USB cards.