Use a USB Hub or Not To Connect Controllers to a PC

USB ports on my computer are disappearing fast as I add controllers, particular those on the front of my computer as my computer set up (BIG dining room table in big kitchen “breakfast” nook) requires a much longer cable run to get to the rear of the computer.

So I’ve already been using a very functional switchable USB hub to control other devices, i.e., barcode scanner, label printer, high-speed paper scanner, USB array mike. https://www.amazon.com/gp/product/B00TPMEOYM/

My question is two-fold. Is a USB hub going to significantly affect controller performance, e.g., lag time, in any way? (I suspect not as Thrustmaster has a scheme for plugging their TFRP rudder pedals into their H.O.T.A.S. flight sticks and advertises their setup as saving USB ports).

The second part of my question is does leaving a controller plugged into a computer forever, whether one is gaming or not, have any noticeable effect on the hardware lifespan of the average controller. The nice thing about the Sabrent USB hub that I reference is that individual USB ports on the hub can be turned on or off, there is a nice blue LED light for each switch for On/Off status, and the whole port is AC-powered (and gets rather warm in use!). Not an ad for the device. I’m just a happy purchaser and would like to know if another one would be a good idea for the mess of controllers now connected to my computer (with more to come! - Honeycomb yoke and separate throttle quadrant I hope when the feeding frenzy for these has died down). If there is a better, more popular USB hub, I’d like to know about it and would get that instead as my second USB hub for the computer.

Thanks for any helpful advice!

I’ve had no issues with mine in FSX/P3D or MSFS2020, Mines a powered one

2 Likes

For question 1 I found this: https://www.quora.com/Does-a-USB-hub-affect-performance

As for question 2 I strongly believe that the electronics inside your peripherals will outlive the mechanics regardless if you unplug them or not.

1 Like

@ChrisMorgan825, thanks for confirming I’m not going to have much of a performance issue. Labeling the ports with a printed strip is a great idea! I’ll have to copy that.

@andhog, great quora link. I like the last paragraph: (repeating link you provided: https://www.quora.com/Does-a-USB-hub-affect-performance

All this being said, under average scenarios it’s unlikely you’ll run into much issues. For example, I’ve used an RGB gaming mechanical keyboard, RGB gaming mouse, wireless gaming headset, and a web cam fine through a usb 2.0 hub. If you have higher end or exotic hardware it’s always good to check on the manufacture’s website for explicit compatibility problems they may list for USB hubs. For example, I know Logitech is problematic with some of their gaming keyboards and mice and VR headset’s accessories use a lot of endpoints, which means you may run out of USB ports on your mother board and require a USB expansion card to be added to your PC.

The other humorous think about checking out the Quora advice is the following:

Limits: A max of five hubs can be daisy chained. If you plug a sixth one in it won’t work.

I don’t think I’m going to go that FAR! The one thing that bugs me about the hub that I got is the USB cable to connect to the computer is not that long and my front ports are all at the top of my tower case - perhaps the desirable length of connector cable is restricted by latency issues, etc.?

Truth is, there IS a performance hit. Now, can YOU see this? No. For every device that is plugged in, it MUST be ‘checked on’ by the PC and/or hub. So the more things in use, the longer this ‘loop’ will be.

This is a FACT. If you have 5 things, your computer WILL check ALL 5. You have 25 things, your computer will check ALL 25. I am ignoring IRQ’s to ‘keep it simple’.

BUT, I TRULY doubt that you will ever see such as these ‘timing loops’ are in the milliseconds.

Here is a much more technical explanation of this:

Cable Lengths:
http://www.yourcablestore.com/USB-Cable-Length-Limitations-And-How-To-Break-Them_ep_42-1.html

What you did not mention and I would ALWAYS suggest is to get a POWERED USB hub. This does 2 things:

#1 - Does not put any strain on the PC’s power supply AT ALL.

#2 - Helps protecting your PC from ‘failed USB devices’ from shorting out your PC’s power supply if some device goes bonkers on you. You will have an ISOLATED power supply.

See: USB Isolation - Things to Consider - B&B Electronics

:slight_smile:

1 Like

As long as you stay within the max cable lengths for the type of USB plug on your particular cable there shouldn’t be any performance degradation.

From a document on usb.org (https://www.usb.org/document-library/cables-and-connectors-class-20)

“Cable assemblies with Standard-series plugs at both ends are limited to 5m. Cables assemblies with a Mini-B plug and Standard-A plug are limited to 4.5m. Cable assemblies with any Micro-series plugs are limited to 2m. The Standard A receptacle to Micro-A plug adapters are limited to 150mm.”

This applies to USB 2.0, if you’re using 3.0 there are probably other numbers involved

1 Like

As long as the usb hub has enough power for all the devices used together you shouldn’t have a problem.

1 Like

As a funny little side note regarding performance of USB:
When I built my computer in December last year I was quite surprised to find a PS/2 port on the motherboard. I thought those belonged to the 90th, so I started googling about what they are used for nowadays. Apparently there are some really hardcore gamers that think that the lag with USB keyboards have a negative impact on their gaming and prefer PS/2 keyboards that use a completely different technique than USB (interrupts I think, instead of the looping over every device). However, I think most of us wouldn’t be able to tell the difference :slightly_smiling_face:

I did mention when I got into the “weeds” that it was a powered “port” - I meant “hub.”

The reason I asked the question is that I was aware that the more things you hook up, the busier the computer or its peripherals are going to be in some respect. But my question was precisely, “Does it ever become rate-limiting in a way that materially affects performance?” and that’s hard to figure out with something like MSFS, which is already pushing performance to the limit in some ways.

I was optimistically thinking that something like a “smart” USB hub is not going to be letting all attached peripherals have full access to the computer all the time. At least at the hardware level if not the software level, it’s probably going to be implementing something like an Observer pattern, restricting peripheral access, and only bringing selected peripherals online actively when MSFS calls for them, e.g., you’re not adjusting the throttle, it’s just being pampered by the hub until MSFS calls for a throttle adjustment, then it gets more attention. So I would think good event handling and using the proper bandwidth USB connector could go along way to letting you connect multiple devices.

I guess my problem is with USB, we’re talking “old” technology here. Maybe someday all sim controllers will be Thunderbolt 4 devices (40 Gbps) and you could probably have a bunch of stuff all attached to your computer through a hub with that technology and nary a noticeable pause. Here’s hoping I live long enough to see it happen! :slightly_smiling_face:

P.S. someone correct me if I’m wrong but I think one Thunderbolt 4 connection can simultaneously handle two 4K monitors, no?! (plus other stuff as well)

1 Like

I’ve had a problem with my USB devices being shutoff in the background for default computer power saving settings. The problem eased when I turned the power saving settings off in the operating system (Win 10). It may be something to look at.

1 Like

I’ve been using a powered USB hub for a few years. No issues with any device plugged into it. Also, I’ve always had the power savings settings for USB turned off as well.

1 Like

Same here. Powered USBhub, no problems.

1 Like

Good thing with the powered hubs! :slight_smile:

The thing with USB devices, is THEY send a ‘request’ to the PC and the PC answers that request.

This is what an IRQ is; ‘Interupt Request’. You have hardware IRQ’s and software IRQ’s. IRQ’s stop the processor what what it is doing and ‘address’ whoever is asking for ‘help’.

I understand what you’re saying and it would be nice if the game asked instead the other way around. Sadly, this is not how it works.

USB is basically a fancy serial port. So the PC reacts to one USB device at a time. And yes, you can burden it down so much that ‘real time’ responses are non-existent. Up to 127 items can be used, but they are ALL handled in a serial fashion.

With what you have? Forget it. You’re fine! What delays are there, you will NEVER notice! Can you tell 1 millisecond time from 1.25 milliseconds? Nah…so do not worry! :slight_smile:

Now, if you ARE having delays, this could indicate HW OR SW issues, such as old drivers or flaky HW devices.

As far as a smart hub, think about it. If your joystick is ‘off’, once you move it, the hub will have to turn on, then send the data to the PC. This is an EXTRA step you now have introduced into the process that was not there before.

And the Thunderbolt? Just like a highway, because it is rated at 55mph/90kph does NOT mean EVERY car on that road will be doing that speed. Joysticks and such will NEVER run at that speed as nothing changes that often. About 32 bytes of data is transmitted per ‘interrupt’. Are you going to move your joystick over 1 million times a second? :wink: Plus the cost of such devices would increase and you will never see any ROI for this either.

Will a SATA I HDD run at SATA III speeds if hooked to a SATA III controller? Nope!

You’re fine with what you got and you will NOT notice any ‘delays’ from PROPERLY operating HW/SW.

Your post DOES show you’re thinking and that is always good! :slight_smile:

:slight_smile:

3 Likes

I use th PS/2 ports for my mouse and keyboard (IBM PS/2 AT keyboard). And there IS a lag as mentioned by those pro gamers. Can they REALLY tell the difference? No.

Can you tell between 1ms and 1.25ms? :wink:

:slight_smile:

Use a powered 3.0 usb x8 hub
Connected:
Honeycomb Yoke
Logitech throttle + pedals + multi + radio
Corsair iCue headphone stand
Xbox usb adaptor

All work fine, no issue :+1:

1 Like

I just had the brainstorm that what I want to do, because the most accessible ports on the front of my computer are just USB 2.0, not 3.0 (what a waste!), is take advantage of the USB-C port (the only one, I think, on the PC) that sits right next to them.

I think that I’ll get a USC-C to PC hub with USB 3.0 ports. If I plug my USB 2.0 controllers into that, it probably should be just as good as if they were each plugged into individual USB 2.0 ports, with the same inherent limitations there as to how many ports can you use on your PC with a very demanding sim hogging CPU time (but since I have an i9-9900K and 16 CPU processes all running at 4.7 GHz, I wonder if even a lot of IRQ’s are going to cause a hiccup? - being ignorant!).

But the interesting thing is that USB-C follows the USB-3.1 protocol, 10 Gb/s. So to not be bogged down by slower USB 2.0 devices, a good high-speed USB hub can create a transaction translator and allocate USB 2.0 devices to a slower pool. USB hub - Wikipedia

Each transaction translator segregates lower speed traffic into its own pool, essentially creating a virtual full-speed bus. Some designs use a single transaction translator (STT), while other designs have multiple translators (MTT). Having multiple translators is a significant benefit when one connects multiple high-bandwidth full-speed devices.

So a really smart USB hub can do some signal processing. The article on USB hubs mention that USB 2.0 hubs can actually uptranslate the speed of slower USB 1.1 to USB 2.0 on the uplink to the PC but unfortunately USB 3.0 and higher are not capable of uptranslating USB 2.0 to USB 3.0 or higher. USB hub - Wikipedia

So I think there is room for a lot of improvement in the future whereby the original device still thinks that it’s in its wonderful IRQ environment but little does it know that it’s trapped in a virtual environment and lots more modern stuff at a much higher speed is really going on when the hub talks to the PC (or the PC gets the word from the hub, maybe the virtual environment will be at that level and an “out-of-date” hub can still try to pass all the IRQ requests it wants along to the PC but little does it know… :slightly_smiling_face:

I shall have to see at least whether any additional hub that I might get is MTT and not just STT (at least I can brag about specs even if makes not a whit of difference - just kidding!).

CORRECTION

The STT vs MTT only applies to USB 2.0 hubs. A USB 3.0 or USB-C hub should be capable of passing data at full speed from each of its client ports with little or no interference from other ports, at least in the transmission uplink to the PC.

The distinction is given here in a quote from a manufacturer’s reply as to whether their USB 3.0 port had MTT: Alternative Multi-TT USB 3.0 Hubs? - #2 by soundklinik - Other Gear - Elektronauts

And the following NY Times 2020 review of USB-C hubs appears to claim that every USB 3.0 hub transmits on the PC uplink at full-speed independent of the other attached devices in the USB-C hubs that were reviewed. The Best USB Hubs and Docks for 2021 | Reviews by Wirecutter

If I’m putting the wrong interpretation on the text, it would be good for someone more knowledgeable to correct me!

You’re doing well! Still, in the end, it will make no difference.

The speed at which your joystick transmits at, is so much slower than the ‘highway’ the data is carried on.

You could say it is like comparing a snail to the X-15, the fastest jet in the world (Mach 6.7/7200 mph).

The data from the joystick will never ‘overwhelm’ your PC; 1 joystick or 10 of them

Granted, you might be able to get 2 nanoseconds faster response, will you ever SEE it or benefit from that? No.

Think about it; How often does the data in your joystick change? 1 time a second? 3 times a second?

In ONE SECOND, USB 2.0 can transfer 6,000,000 bytes! Even at 128 bytes in a single joystick data set, USB 2.0 can send 46,875 data sets in ONE SECOND! You will NEVER move your joystick that many times! NEVER! :wink:

This is why I say IGNORE the ‘faster USB’ - It makes NO DIFFERENCE!

Do not worry about it - You are just fine with what you have!

:slight_smile:

You might want to get a powered hub though, as i learned from experience of running multiple devices, effectively from a single port, some rather odd controller behaviour can result.

I forgot to plug my hub in once and a WH HOTAS, MFG Crosswind pedals and a G13 gamepad just didn’t play nice together. Their behaviour improved dramatically however, once i’d discovered my error.

Thanks very much for the advice and the assurances. I didn’t make clear in my OP that effectively if I got a hub in my original plan, I was going to be plugging it into a USB 2.0 port on the front of my computer. The only USB ports left open are just three 2.0 ports and a USB-C port on front and just one USB 3.0 port on the back.

The worry in my original post was basically what happens if I plug FOUR USB 2.0 controllers into ONE USB 2.0 port thru a USB hub.

What I’ve decided to do is get another powered, switchable Sabrent USB 3.0 hub, a USB 3.0 to USB-C adapter plug and plug the hub thru the adapter into the front of my computer. All the flight controllers that I plug into the four USB 3.0 ports on the hub should be guaranteed to behave as if they were talking to the computer through their very own port and I can switch the whole thing off by the individual port switches on the Sabrent and unplugging the AC adapter, saving some juice (and global CO2) most of the hours of the day when I’m not gaming. I can probably daisy chain on at least one more powered USB 3.0 hub to gain additional ports if I need them without worrying about controller performance on a USB 3.0 daisy chain and the powered aspect of the Sabrent hub and its powered USB ports allows me to charge any USB device that needs charging like my cell phone, hearing aid devices, or watch, if I want. *** CORRECTION BELOW

And I’ll free up the (“useless”) three USB 2.0 ports on the front of my computer, still having just that one remaining USB 3.0 port open on the back of my computer. And I’m going to gain a bunch of powered USB 3.0 ports at the expense of my one USB-C port built directly into my computer. (no PCIe slots left for a USB card and I’m not sure if such would be as powered as those thru the hub). So perhaps I shouldn’t have worried about controller performance originally but I’ll be gaining a lot more expansion and versatility if I use my USB-C port for a powered, switchable USB 3.0 hub and would upgrade in the future to a USB-C hub if an inexpensive, powered switchable one wanders by! The whole purchase for a USB 3.0 hub and a 2-pk of USB 3.0 to USB-C adapters was $25 with free shipping.

Correction

The product literature says,

This 4-Port USB 3.0 Hub does not charge your devices (it can only sync).

and

For a stable connection, the devices connected to the 4-Port USB 3.0 Hub must not exceed a combined current of 5 volts 900 mAh.

Apparently, the supplied power adapter is only to assure that connected devices have 900 mAh current to divvy up amongst themselves. Normally, a USB-A port should be able to supply up to 500 mAh at 5 volts. Sorry for the egregious error. I do have devices like a barcode scanner and a (small) USB microphone array that are hooked up to and powered by the Sabrent hub that I already have (so I guess I haven’t exceeded a 900 mAh total current draw yet). https://www.techwalla.com/articles/what-is-the-power-output-for-a-usb-port

Hi guys. First time poster here.

As a useful aside, I found that having my Thrustmaster TWCS + T16000 connected prevents my PC from properly going to sleep (and staying asleep). This was true of my old PC, and it’s also true in my new build. If I unplug them, the sleep behaves as it should. Consequently, having a USB hub with independent switches is really useful, because you can turn off those devices independently, without having to pull them from the ports. I bought a hub for this very reason. And I don’t notice any difference in performance, using the hub.

1 Like