Phase One actually uses 10G ethernet on their industrial camera line. But 10G ethernet takes a lot of space, heat, and power and the IQ4 needs room for things their industrial cameras do not (like a screen, UI, and on-board storage).
Three methods of tethering the IQ4:
- USB-C is fastest and is really very fast (especially considering it's sending 150mp or 37.5mp raw files), but has cable length limitations (not because of P1, but because of the nature of USB-C)
- Ethernet (on the IQ4) is about as fast as USB3 was on the IQ3, but both provides lots of power (provided you're using a POE), and allows very very long cables.
- Wireless: will always be slowest of the three, but requires no cables. At this point it's not really worth mentioning other than as an to-date-under-fulfilled promise of the platform that I still expect to get much better. Currently it can't generate it's own ad hoc network and it can't do a good JPG-to-computer-immediately-via-wireless-RAW-to-card-and-also-computer-as-time-allows workflow that could make wireless-tethering more useful.
If you are seeing any instability with ethernet tethering at all you should troubleshoot with your dealer. It should be incredibly stable. I say this from both theory (it was brought over to the IQ4 from the industrial line where multi-camera systems should hundreds of thousands of images in a row in harsh environments and a single tethering issue incredibly costly) and practice (a large number of our high-volume clients using it every work day, some for nearly a year now) as well as our own in-house testing.
However, like any networking (which is what ethernet tethering of an IQ4 is) the equipment in between (cables, router/modem) and network settings are critical to a fast-as-possible and totally-stable experience. That's where you'd want to work with your dealer to troubleshoot (along with the low, but non zero chance that your unit has a funked up ethernet port; it's the least likely cause of issues here in my experience, but of course must be considered).
There are a few remaining limitations/issues with the IQ4 as of today (notably: no ad hoc wireless review/control as with the IQ3; P1 is swinging for the fences to do something really good, and it's taking much longer than anyone would want). But ethernet tethering stability is not one of them.