Performance of the System alone does not solve such issues.
The fastest CPU can be blocked by several things like e.g. bad drivers resulting in too high DPC latencies.
Then the system is fast enough for benchmarks.
But not fast enough to react quick enough on an audio workload which has realtime requirement.
For a simple Benchmark it does not matter when the data is being processed.

For audio the timing is critical, clear?

There are a few root causes for audio drops
- 3rd party chip not supporting USB3 transfer mode well which is used by MADIface driver.
  See UFX III manual which USB3 controller chips are known to work well.
  Try all USB3 ports on your mainboard.
  Maybe this leads you to a better USB3 port coming from chipset or one of the better/supported USB3 controller.
  Good strategy: isolate the UFX III behind an otherwise free USB3 controller or get a separate PCIe USB3 card
  with supported USB3 chipset, e.g. Sonnet card with FL1100 controller.
- BIOS: energy saving not disabled (C-/P-/T-States, C1N).
- Bad energy profile used in Windows, use high Performance or activate Ultimate performance (google for it)
- bad drivers, too high DPC latency (measure with LatencyMon)
- energy saving of nVidia cards, produces audio drops even if DPC latency appears low (only on desktops: disable with powermizer tool)
- thermal issues: CPU throttling caused by heat (observe heat and CPU clock using HWMonitor)

See also:
https://forum.rme-audio.de/viewtopic.ph … 00#p214600

There are a lot of such threads in the forum about how to deal with such a situation, including good background information.
I gave you an intro and some links which contain more information and also further links.

Sorry, but you are asking the wrong questions. Why?
Thunderbolt won't change anything if the root cause is somewhere else.

Make a backup. Measure where you stand now (LatencyMon).
Make a checklist what to look for.
Change only 1 thing and remeasure.

You can get a Sonnet USB3 card with FL1100 chip but it is not sure whether it will help if you had only bad settings in the BIOS. So I would 1st ensure to use proper USB3 port on your computer and whether the settings are ok.
The last measure of resort is, to eventually get this Sonnet card, but this also only helps when the settings are correct and if the computer has not too high DPC.

The Sonnet card has also been mentioned multiple times in the postings and even if you would need to look at Sonnet it won't take more than 3-5 min. The technical specs of each card clearly show you that only 1 card has FL1100 chipset.

If this is all too much work for you, sorry, but then you should have bought a turnkey PC for audio.

I can imagine your situation well. However, I only have limited time as I am a private person like you.
You can learn much from reading my postings about that topic.
In a good case of luck, its only a few BIOS settings in the area of energy saving.
Or to ensure that you use High-Performance energy profile in windows.
Or to use a proper USB3 port on your system which comes from Chipset of mainboard and not a 3rd party controller which does not fully work according to USB standards. And .. you have to measure ...
But now I repeat myself again.
The information IS already in this forum, I gave you short overview into the thematic and links.
No need to tell it over and over again, pls be so kind and use the existing resources.