New ASI174 camera, but no USB 3.0 yet........

[Astroboffin]

Hi all,

I am interested in one of these new 174 cameras, and am going to upgrade in the near future to a laptop with USB 3.0, but for now will have to use on USB 2.0.

So my question is will I get the same frame rates from this camera on USB 2.0 as I do currently with my ASI120mc, I realise the max resolution is much more on the new camera, but if I adjusted that to the same as the maximum on the ASI120 would the frame rates be the same, or more or less??

As I don't want to lose out while having to use on USB 2.0 until I get my new laptop.

My second question is that on the ASi120mc there are about 10 pre set resolutions, but on this new one there are only 3, so if you don't want to use the maximum, do you have to use the next one down which is 640x480 which seems a big drop? What aren't there more preset resolutions inbetween?.

Thanks in advance

Regards

AB

[JamesF]

As far as I'm aware, the preset resolutions on the ASI cameras are just a software thing for convenience.  In fact you can set an ROI of pretty much any size you like as long as the total number of pixels is a multiple of 1024.  I must admit that I've not checked to see if it looks like the preset resolutions are done on-camera and others are done in the driver.  It may be (and this is just a random idea) that the 174 sensor and its support circuitry can only handle the three stated resolutions.

I can't see any reason why the 174 should perform significantly less well than the 120 on USB2 at the same image size (that is, assuming they're transferring the same amount of data to the pc at those resolutions).

James

[JamesF]

I realised I actually have a 120MC and 174MM on my desk at the moment, so I thought I'd give it a go and compare the speeds as my desktop has both USB2 and USB3 ports.

Somewhat to my surprise it turns out that the 174MM refuses to talk to the USB2 port at all.  I have no idea if that's just my desktop, or if it won't talk to USB2 systems at all.

James

[Astroboffin]

I realised I actually have a 120MC and 174MM on my desk at the moment, so I thought I'd give it a go and compare the speeds as my desktop has both USB2 and USB3 ports.

Somewhat to my surprise it turns out that the 174MM refuses to talk to the USB2 port at all.  I have no idea if that's just my desktop, or if it won't talk to USB2 systems at all.

James

Thanks for the test, it does say on the ZWO website that it IS backward compatible with USB 2.0, so that's a strange one....maybe others can test the 174 on a USB 2.0 port just to see, I will be upgrading but not until may or June, so just wanted to get the camera and run on USB 2 till then.

Thanks again

AB

[JamesF]

I think there may be some compatibility issues, just as there were with the USB2 cameras.  I'll try to find something else with USB2 ports on that I can test later.

James

[Astroboffin]

I think there may be some compatibility issues, just as there were with the USB2 cameras.  I'll try to find something else with USB2 ports on that I can test later.

James

Much appreciated, thanks

AB