• Registered: 2018-06-10
  • Posts: 4

Topic: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

Howdy!

I'm a proud owner of several RME products - they are really a cornerstone of our large rig and have been foolproof for many, many years.  Great work!

I have several questions.  I will call them out with a '[Q]' tag so they are easy to answer. 

But first, I have a rig:

  • MBP 2015 Retina (fastest I could find!) - it has 2 USB3.0 ports only.  It also has a thunderbolt port that I'm not using currently.

  • Push 2

  • 4x OpenDeck USB MIDI controllers (USB2.0 connection only)

  • RME UFX

  • Expert Sleepers ES-8 (USB2.0 dc-coupled audio interface)

So that's a total of 7x USB ports required.  I only have 2x and a thunderbolt port.  The UFX is, I think, utilising the highest bandwidth due to the track count.  About 8-10 inputs and 2 outputs being used but then we have some ADAT expander connected for another 8x op channels on the RME.  Then I aggregate the RME with the ES-8 (also connected via USB) using Aggregate Device.  This part is working fine!  The OpenDeck boards - even though there are 4x, are pretty low bandwidth, comparatively.

[Q] So what's the best approach here? 

  • 2x 4 port USB hubs (3.0 or 2.0?) and connect everything through one of these 2 hubs

  • 1x 7 or 8 port USB hub (3.0 or 2.0?) and connect maybe the UFX to a dedicate MBP port and everythign else to the hub

  • 1x thunderbolt to USB interface

  • ...or some combination of the above?

I'm also not an expert on USB so much though I do believe it is pointless to use a USB3.0 hub if all of the gear is 2.0... though this is less future proof.  I think the USB3.0 stuffs is essentially handled separately from any USB2.0 devices - they are even different wires... so I'm thinking if I ever get a 3.0 device, that's basically free bandwidth.  [Q] Is this true?

Another option, if it matters is to get a 3.0 hub and a UFX+ with USB3.0... connect it and the other 2.0 USB peripherals to the same USB3.0 hub... Or maybe use the thunderbolt port for the UFX+ and then the ES-8 through a dedicate USB port on the MBP while the other port can have a hub connected to handle the less critical (well, not really, but I should say rather 'lower speed') devices like the USB MIDI controllers and the Push 2 (though I hear it is a pretty hefty device in terms of bandwidth due to the screen and live updating, etc.)  These options (with the UFX+) would have me buy 2x new UFX+ though I really do not want to spend the money again unless there is some measurable improvement or I actually have problems.  I believe this should allow for more bandwidth (?) though I don't know if it matters.  [Q] Do any of these seem like valid options or that would give me more headroom for my particular configuration?

I'd really like to quantify - so I know a particular selected configuration is going to be reliable and I'm not pushing some edge of bandwidth here... at least to know which things should be 'hubbed' together, if at all.... [Q] are there any tools I can use to monitor USB bandwidth on each port or even the effects of what the hub might do?

Any help to these questions is greatly appreciated!

Thanks kindly,
Phil

2 Reply by MC

  • MC
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Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

USB ports and available bandwidth are unclear to many. On top the industry sells multi-port hubs (up to 15...) as if this is the guaranteed way to connect as many devices as you like.

The truth is different. It starts with looking at the USB2 port within a USB3 port. This port is separated from the USB 3 port (you are totally right here). Using a USB 3 hub and then connecting a USB 2 device you are using the same USB 2 port within the USB3 port of your computer. Or in other words: there is no translation of USB 3 into USB 2, which would give you tons of USB 2 ports just by using more and more USB 3 hub. Instead you split one's port resources further and further, no matter how many hubs you use.

That said when connecting a UFX to a USB 2 port, the resources of said port are nearly all taken. This is not only about bandwidth, but also about available endpoints etc. Using a hub already consumes resources. Connect the UFX to said hub and you will get problems to have other tools like dongles, keyboard/mouse wireles etc. working.

This is astonishing for many being used to see multi-port hubs presented as if they will just work, no matter what you plug in. I have no clue how to use a hub with more than 7 ports in real-world without running into problems. Usually I can't even use 7 ports, because I always have a multi-channel interface connected on one port already. And with an ADI-2 Pro in stereo mode you can easily max out the USB2 port with only two channels by upping the sample rate to 786 kHz...

So if you have tons of USB2 stuff to connect, USB 3 doesn't give you any advantage. Except that USB 3 is still waiting to being used when USB 2 is maxxed out already.

Your situation is common for most laptop users (even me under Windows): the internal design is two USB 3 ports, which come from one internal controller and have one USB 2 port each. And one quickly runs into problems.

Fortunately these days one can extend the number of available ports in two ways:

- a USB-C based multi-port hub. This one uses the additional USB controller in the USB-C/Thunderbolt controller port.

- an external dock using USB-C Thunderbolt 3. Those docks have their own USB chipset(s) that operate from TB 3 (equals external PCI Express). If made correctly such a dock can have more than one USB chip via TB3, instead of one and then spreading them all out via serial hubs. For example my OWC TB3 dock has two USB3 Fresco chips which drive 5 USB 3 ports, so I not only have double USB 3 performance, but also two independent USB 2 ports that I can spread out via hubs again.

- Said dock also has another TB3 port, so you loose the one on your notebook (if there is just one, mostly the case) but  get another one at the dock to connect anything that requires or uses TB3 performance.

If you turn to the UFX+ you could use any of those unused USB3 ports, or connect it via a TB3 to TB2 adapter to the computer's TB port, or when using a dock to the dock's TB output. I mentioned this here before: I use the Apple TB3 to TB2 adapter behind the OCW dock to connect an LG widescreen TB2 monitor, then connecting the UFX+ via the monitor's second TB2 port. Works perfectly. And it should, as this is all PCIe based.

Hope this helps.

Regards
Matthias Carstens
RME

MC's Website

3 Reply by rabidelephant (edited by rabidelephant 2018-06-10 13:46:57)

  • Registered: 2018-06-10
  • Posts: 4

Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

Thank you Mattias for the quick response.  And very informative indeed!

The laptop I am using only has TB2 (link to the exact machine is here), though I do not think that is an issue since they are still much faster than even USB3.0.  This particular machine also has 2x TB2 ports, which I assume use separate controllers.  I just don't know if some the same details above hold true when talking about TB2 and not USB C or TB3. [Q] Does TB2 also have its own USB controller?  Or is it translated?  And what happens if I were to get, for example, as TB2 dock with several USB3 ports - will I run into similar issues connecting several USB2.0 devices to these connections?

I think the solution is to indeed hang something off off these super-duper fast TB2 ports that are currently unused and just use a USB hub for the slow USB MIDI controllers I have (which are sucking up 4x ports).  What do ya think?  [Q] Could you confirm that TB2 would still be the way to do?  And if you could, anticipate any problems I might see with TB2 based on your experience.

[Q] Are there any 'enumeration' or other connectivity issues with TB based expanders/hubs, etc that I should be aware of?  Basically I want to leave all of these things plugged in - but if somehow they are refreshed and potentially re-numbered, then the rig will no longer function as it should.  I am new to the whole TB thing, to be honest.  I'll do a search for thunderbolt on the forum here in the meantime and see what knowledge base has formed around it.

[Q] And finally, are there RME-recommended hubs for expanding out a TB2 connection to connect USB interfaces to?  I also read that TB3 can be plugged into TB2 connection (hopefully I'm not missing something here) which would potentially open up another set of options for me to use and select from.

I found a TB2 to USB3 adapter/dock (the RocketStor 6324U Thunderbolt 2, Quad-Port USB 3.0 Adapter) that says it has 4 separate USB3.0 controllers (which I would assume would mean also separate USB2.0 controllers if they are part of the same IC).  So for something like this guy, while TB2 couldn't handle all USBs at full USB3.0 bandwidth, it could easily handle 4x USB2.0 connections, at max bandwidth, technically.  But really, I'd only need separate USB controllers for just the ES-8 and the UFX (the audio interfaces).

Thanks again!
Phil

4 Reply by MC

  • MC
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Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

TB2 is not USB-C, there is no simple adapter to USB available. Such an adapter would be a TB2 (= PCIe) adapter to USB 3 or 2, which IMHO doesn't exist. The way to go here is with a dock again. I can not recommend something specific, although I used a Caldigit TB2 dock before that always worked.

Regards
Matthias Carstens
RME

MC's Website

5 Reply by rabidelephant (edited by rabidelephant 2018-06-10 15:36:26)

  • Registered: 2018-06-10
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Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

Again, thanks for the quick reply - and on a weekend.  I'm in a bit of a time crunch to get this working before an upcoming international move!

Yea, I read that only TB3 adds the USB natively.  So the TB2 would be a sort of 'convertobox' of sorts - which I guess a lot of PCI(e) USB cards are.

So the recommendation then would be something like:

MBP USB3.0 Native Port connected to a USB hub which has the low-priority devices installed: thinks like the USB MIDI devices (which would need a hub regardless) and the Push 2. 

Connect both RME UFX and the ES-8 audio interfaces to some TB2 dock with USB 3.0 ports on it (but with dedicated controllers for ea. port - some do not and share the controllers).

And that's it!  Or at least one option. [Q] What do you think of this?

[Q] I am only planning to use 1x MBP USB port since after your comment I confirm that they share a common USB 3.0 controller (which would mean the USB2.0 is shared too).  Is this correct or should I be using both MBP USB 3.0 ports for USB2.0 peripherals?

Yes, the Caldigit is on my list.  I'm mainly just trying to find docks that have separate controllers per USB port - I even found one TB2 dock that has a limit on USB peripherals (even though they are USB3.0) to sub-USB2.0 speeds, which I don't understand!

I also read that some TB3 dock manufacturers say that you can plug it into a TB2 port with adapter and it still works.  Does that make sense in terms of the USB C capable peripherals they have on-board?  Unless they are not utilising the TB3 built-in USB, this doesn't seem to be correct.

And I just thought of another... I could potentially use a TB2 to firewire adapter to run the UFX...  this would not require a full on dock and just some passive adapters/cables, I believe.  [Q]  Are there any known issues with aggregating 2 interfaces - one connected via FW and another via USB?

6 Reply by rabidelephant (edited by rabidelephant 2018-06-10 15:50:36)

  • Registered: 2018-06-10
  • Posts: 4

Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

After looking at these docks and whatnot... they're several hundred USD and up... then I've got another piece of 'stuff' to carry around and lots of extra connections that could come undone (TB connectors are especially dodgy IME).

So maybe the 'right' solution is to go with the UFX+.  I have option to still use it via TB2 port but I also have the option to 'snag' the USB3.0 on the MBP and use the other USB port on the MBP for USB2.0.  This way I don't have a dodgy TB connector on a live rig.  I recall it is similar to FW800 in terms of being a little unreliable and loose.  I used to have to tape the cable in and I'd prefer not to have to do that.  USB connectors are very solid and I've never had a full size USB A or B connector fail (knock on wood).

As the rig is right now I have the UFX plugged into one of the MBP ports and the other MBP port has a 7 port hub with the 4x opendecks and another audio interface ES-8 along with the Push 2 which is not slouch in terms of data it needs... and while it is working, I am noticing some overload/digital 'oh no you don't' noises sometimes and I have to stop and restart the transport.  I am pretty sure it is related to the overload of bandwidth since all devices are technically going into the one MBP USB (and 2.0!!!) controller.  At least this way, I take the UFX onto the USB3.0 side of things and it's 'isolated' (I think!) from all of the other USB2.0 stuffs - and that should be a marked improvement. big_smile

7 Reply by MC

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Re: USB/Thunderbolt Hub recommendations for RME UFX and ES-8 and ...

> I also read that some TB3 dock manufacturers say that you can plug it into a TB2 port with adapter and it still works.  Does that make sense in terms of the USB C capable peripherals they have on-board?  Unless they are not utilising the TB3 built-in USB, this doesn't seem to be correct.

Of course that is correct. TB2 is still PCI Express, and with TB3 docks not a single one uses the included USB port as that one is not available while doing TB3. All USB must be PCIe based additional chipsets.

Regards
Matthias Carstens
RME

MC's Website