Hi Miguel,

apart from your specific question, I have taken the liberty of addressing a few other points further down that are related to the question of whether one should upgrade to a UFX III, in order to provide other readers with a more comprehensive overview.

Generally spoken, you can assume that RME would not use USB3 if the product did not function perfectly with it.
Here are a few examples from my experience with my UFX+ over USB3 (as I have no TB).

I have not experienced any general issues with USB3, only a few things explained below, that can easily be solved and which is nothing unusual according to the complexity of today's computers. Incompatibilities can also happen with TB.

Regarding USB3 performance. I conducted a "synthetic" Cubase benchmark with a 400-track project containing over 800 Steinberg VSTs (2 VSTs per track), and it performed excellently without any dropouts at both 44.1 and 96 kHz.
The system load was comparable to a RayDAT PCIe-based card. You can find more details about this benchmark here: https://www.tonstudio-forum.de/blog/Ent … cks-de-en/

If you should experience USB3 issues, a possible solution is to purchase a USB3 PCIe card, best with supported USB3 chipsets, which are known to work. You can find more information about this in the manual. It is generally a good strategy to isolate your recording interface behind such a card.

In my case: initially, I had no issues using the USB3 ports from the Intel C612 Chipset to connect even two UFX+ units. However, as I connected more USB devices, I encountered problems. This is when I had to isolate two UFX+ and an ADI-2 Pro behind a Sonnet PCIe card with supported FL1100 USB3 chips. You can see my system setup here: https://www.tonstudio-forum.de/blog/Ent … mponenten/. This Sonnet PCIe card uses still the FL1100 chip: https://www.sonnettech.com/product/alle … 4port.html
Since using the Sonnet USB3 card (the pro model with 4x FL1100), I have not had any issues anymore. Even with two UFX+ and ADI-2 Pro connected to it.

Graphic cards for gaming can be another reason for audio drops (not USB3 or TB related). After upgrading my system to an nVidia card with RTX2070 Super, I got occasional audio glitches independent of CPU load or DPC latencies. This was related to power saving on this nVidia card. This could be solved with the tool powermizer that disables power saving on the card.

As for the differences between Thunderbolt and USB3 in terms of RTL, you will have to decide for yourself whether these differences are relevant to you. You can find more information about this here (snapshot from an Excel):

Please note:
- with higher sample rates, the converter latency values become even smaller
- that the values provided in meters or centimeters refer to the "speed of sound" at 20°C. To give you a real-life example of what these ms values would mean in terms of distance between musicians on stage
- as there is no UFX III with TB I can only show the difference between USB3 and TB based on values from UFX+

For other differences between the UFX+ and UFX III, please refer to my comparison Excel sheet here:
https://forum.rme-audio.de/viewtopic.ph … 26#p186126
These differences include very fast converters, improvements in the analog section, USB3 CC mode for all I/O ports, FS clock, track names for DURec, remappable keys (33 functions), and lockable keys. The latter two features were first introduced for the Fireface series by UCX II. Additionally, both ADAT ports on the UFX III are switchable to optical S/PDIF.

What I also like about USB3 is the maximum cable length of 3m. That's 1m longer than Thunderbolt and allows me to have the rack on the left and the computer on the right side of the desk. With a 1.5m wide table, you already need around 3m if you have to cable along the wall or along the corners. I've had good experiences with premium cables from Lindy here, which offer triple shielding and in my opinion provide good connector quality. The price-performance ratio is very good compared to the very expensive (in my opinion overpriced) TB cables.
https://www.lindy.de/3m-USB-3-2-Typ-A-a … ;ci=800504

If anyone is seeking for the latest and greatest in terms of monitoring, technical specs and features: an alternative option would be to consider purchasing an ADI-2 Pro FS R BE or ADI-2/4 Pro SE. I have discussed the integration of such a reference converter in my blog here: https://www.tonstudio-forum.de/blog/Ent … our-Setup/

Additionally, some information about the benefits and features and a model comparison (ADI-2/4 Pro SE not yet in) here:
https://www.tonstudio-forum.de/blog/Ent … ses-EN-DE/

If we ignore the question whether there are audible differences in the D/A conversion between UFX+/III and ADI-2* (you should find that out for your ears in your environment): these devices offer for sure the best technical specifications, various A/D and D/A filters, and a variety of innovative and useful functions for monitoring through speakers or headphones.

Other benefit: they also provide implicit protection against high volume levels due to level mismatches (see also forum https://forum.rme-audio.de/viewtopic.php?id=25399), if one has not already addressed this through appropriate measures.
With an ADI connected behind a digital output, in TM FX, the output level can be left at 0dB for the Main Out. The ADI remembers the last volume setting and increases the volume with a slight delay when switching between speakers and headphones, which is enough to reduce the volume.

I hope that this overview will help you in deciding whether to stay with the UFX+ or upgrade. The UFX+ remains an excellent interface and delivers the lowest RTL values, even though the differences are minor. Your setup seems to be functioning well, and technical specifications aren't everything in this world.

I wouldn't tell at this point because I think you must come to your own conclusions whether some features of your UFX+ are more important to you than having the latest features of the UFX III.

To have TB and USB3 might for some people be more important compared to USB3-CC, FS Clock, quicker converters. The converters of the UFX+ can't be called slow as well. Around 50% of an already small latency is less compared to converter latency of a Fireface UC (older design).

I have already mentioned some differences, you should write them down and evaluate / weight them for your work.
If you are simply recording something through some Mics, then converter latency isn't an issue.
More interesting perhaps for direct monitoring on the device, but as I said, the converter latency of the UFX+ was already very good and now it is a little better closer to whats physically possible.
Look at the converter latencies of ADI-2 Pro or ADI-2/4 Pro SE, you will see much more isn't possible.

Well, thats another story. Why not, the same do people say, who use USB based products successfully: "Never change a running horse".

But if you are looking for a new product or want to upgrade because of one or some of the new features that the UFX III offers, well then I see no hindering point using USB. But this seems to be a hindering point for some people, most likely based on hearsay without having tried it on their own.

BTW: regarding "as long as possible". I will stick to Windows 10 as long as possible

Back to TB vs. USB … I really wouldn't worry too much, I am using USB based RME products now for around 7 years. Many other customers do so as well. I can't see any real benefit of PCIe or TB over USB. USB works reliably, and it is easy to get a system with USB2 or USB3.

If you stick too much to the position "it has to be TB" then you only limit yourself regarding purchase options.

My experience with USB based gear summarized in this thread: https://forum.rme-audio.de/viewtopic.ph … 39#p201239

Whenever it comes to audio / real-time processing, you have to look to get a good working mainboard, not any mainboard will do well.

You also need the skill to find a CPU/mainboard combination, where the PCIe sockets (that you want to use) have dedicated PCIe lanes which are not shared with other components to avoid any side effects.

Next thing is driver support, DPC latencies, sometimes maybe even the BIOS.

If you got a mainboard that has some "flaws" in areas which are important for audio, then it creates the wrong impression, USB wouldn't be well suited for audio where actually it was the fault of the mainboard.

Usually, USB works very well, single cases on this or other forums shouldn't be generalized too far.

But if TB is simply your preference, then you could have perhaps a look at the used market (eBay, …).

Regarding the UFX+ vs the UFX III debate:

1) Only the thunderbolt driver supports the pitch function which is one advantage of the UFX+ over the UFX III. The USB3 transport modes of the MADIface driver do not allow for the pitch function on the UFX III.

Question: Is that a significant negative for the UFX III as compared to the UFX+, or has RME addressed this issue on the UFX III with an improvement I'm not aware of?

2) A past big negative of the UFX+ with Pro Tools; the i/o is limited to 32ch, and only the 1st 32. That means MADI starts on ch30-31, making it virtually impossible to use MADI with Pro Tools. RME has said in the past that it was on their to-do list, but it had been for years and they were taking their sweet time developing a way to rearrange the order of i/o for ASIO and Core Audio.

Question: Was this issue with the UFX+ ever resolved?
Question: Also, does this issue exist on the UFX III?

If lacking the pitch function on the UFX III isn't a big deal, then I think it may be better for my daughter because it will have a longer lifespan; I'm told by electronic/electrical engineers on another forum that capacitors start to degrade around 20+ years and around 30+/- years they tend to go out with the max lifespan about 40 +/- years regardless if the unit is being used or not. They said, generally speaking, unless you want to do a cap job on your vintage gear, that you should plan on replacing your gear at or before the 20-year mark because in audio you don't want to take any chances of capacitor degradation affecting sound quality.

I am now considering one of these to purchase soon. Both brand new, including the UFX+ (the last one left with a dealer I know):

1) 2023 UFX 3 for $2,820 (20-year lifespan before cap job)
2) 2019 UFX+ for $3,025 (16-year lifespan before cap job)

Which would you choose and why?

Thank you.

Just a quick update on Thunderbolt use with the UFX+. Looks like Intel is dropping support for TB1 & TB2 devices. I was operating under the assumption that adapting Thunderbolt 1/2 to Thunderbolt 3 effectively made it a Thunderbolt 3 device to the host. But apparently it is still seen as Thunderbolt 1/2, and support is finally dropping across basically all PC (windows) hardware.

My guess is that Apple will support for many years to come, as TB1 & TB2 devices were plentiful in their ecosystem. But eventually I'm sure even they will drop support. I just didn't understand that that's how adapting Thunderbolt worked, so if anyone is considering using an RME interface + Thunderbolt for longevity. You'd be best off buying an HDSPe card and using it in a Thunderbolt enclosure. As Thunderbolt enclosures are likely to updated forever, and PCIe continues to be backwards compatible.

My Asus ProArt Z690-Creator Wifi no longer supports TB1 & TB2 as of a few BIOS updates ago. After updating I can't get my interface to connect over Thunderbolt & there's no way for me to downgrade due to also updating my Intel ME firmware. Basically I'm out of luck when using TB on my UFX+ moving forward. At least RME had the foresight to co-implement USB3 on the interface. And luckily on my new Intel platform it appears to be working without USB Diagnosis errors when isolated on its own USB bus.

But is it possible to use the UFX+ via Thunderbolt with a new build PC System (2024) hat only has TB4 Ports?
Thank you!

ok, so no adapter etc will do this?

Can I put in an extra PCI Card with TB3 Ports to use UFX+ for further use with Thunderbolt?
On my actual system I use it with the StarTech TB Adapter.

Thank you.