I haven't tried this extensively with my current Pi4 setup, but my ZWO USB3 cameras had no trouble with my previous Pi3 setup, which is USB2. If you want, I can try tonight how they behave when I plug them into the USB2 ports on my Pi4 and let you know, if that is any help.
Besides, the hub on the ASI1600 and ASI183 are USB2 hubs, which then feed through the main USB3 cable and I am routing my USB3 ZWO guide cam through that USB2 hub, so I don't think that would be a problem, especially when you are using a ZWO like the ASI1600 with a 256MB buffer in the camera. The ZWOs seem to be very tolerant in either direction.

Backfocus readjustment is a different issue, of course, but at some point, you will have to bite the bullet anyway. The ASI1600 will work with 31mm filters down to f4, I believe, so you likely would not have to change the filter wheel setup, only the backfocus.
Happy to help with testing the ZWO USB2 connectivity, if you want.

Jo

That would be much appreciated if you could try your Zwo camera on the USB2 port please.

Backfocus details...

Flat field flattener 55mm (to achieve)

Atik 314L+ 13.1mm
Gerd Neuman drawer 21.9mm
ZWO OAG 16.5 mm
current (Atik+Gerd+OAG) = 51.5mm
to 55mm is made up of thin rings

From what I'm reading the Zwo cameras have 6.5mm back focus which is about half the Atik314

I use my ZWO cameras with both USB2 and USB3 ports without any problems at all.

A shorter distance from the sensor to the outside of the camera (mind, this is NOT called back focus because that is the necessary distance between the flattener and the sensor) is good. You will need to add some rings to make up for the shorter distance to be at the correct back focus distance again.


Wouter

I tested the ASI183 and the ASI1600 on my Pi4 using USB2 connection only. I sent you a PM with a Dropbox link so you can inspect the screenshots and the FITS files.

No problem at all! I would switch out your Atik for one of the ZWOs. They work flawlessly in my hands.

Thank you so much, looking at them now.

Side track to this thread..
I've read a lot about the CMOS sensors, the amp glow etc... the pros the cons, but there is something I still can't get my head around and it's about cooled vs uncooled on the ZWO cameras.
Is there a huge difference in terms of performances between the two? Knowing that I do not use the observatory in summer at all.
ZWO ASI 183MM USB 3.0 Mono Camera £669
ZWO ASI 183MM-PRO USB 3.0 Cooled Mono Camera £937
£268 difference in price

YES!!!!

Huge difference!

There is nothing like cooling your camera down to 30-35 degrees below ambient to reduce thermal noise.

I accidentally forgot one day that I had switched off the cooler and imaged for an entire night without cooling. Essentially, the images were ruined. I could hardly make out my target amid all the thermal noise.
Now, I am imaging from a Bortle 8/9 area, essentially middle of a major city, but even so the difference between cooling and not cooling was night and day.
This is the main reason why I am rarely using my DSLR these days for imaging. I have adapted my Nikkor lenses to mount them on my ZWOs.

When you are getting a new camera, DEFINITELY get a cooled one. An absolute MUST, unless you are living in Antarctica, and even there global warming will make cooling a necessity soon.

cool beans, thanks for the help everyone.
I'm going to sleep over it and decide if I get the Atik repaired or not, weight the pros and cons of a Zwo upgrade (if I go down that route, I'll upgrade the Odroid C1 to the N2 which has USB3 and is way more powerful)

Stay tuned...

Just to let you know, I run my setup with a ODroid N2 with ZWO ASI1600MM Pro (USB 3). No problems here.

Good luck with your decision.

El Corazon - What kind of frame rates to you get with RPi4 and a ZWO USB 3 camera in video mode, in the CCD Section?

The new ASI533MC fails to get even 2 FPS. and downloading an image takes just under 3 seconds. Something is amiss as it is much slower than the ASI120mm mini where I can get 20FPS

I am not sure anything is amiss here. The ASI120 has 1.2 MP, the ASI533 has >9MP. So it makes sense that the frame rate is 10x slower for the ASI553 than for the AS120. ~10x more data are transmitted per frame.

That being said, I am not using the video capture in Ekos, because it is pretty slow. Unfortunately, I have not been able to get FireCapture to run the Rpi4 or PlanetaryImager. Their architectures are incompatible with the armhf architecture of the Rpi4 and when I am adding amd64 architecture I have other conflicts with dependencies that continue to crop up. I am using a miniPC with amd64 running Ubuntu for video capture purposes. The Rpi4 in my hands only works well for still captures.

On your N2, could you please install github.com/mvp/uhubctl and let me know if it cuts the USB port power correctly or not please?