Strange result from my new ASI 120MM-S

mattw

Hi guys.

Just took delivery of my new 120MM-S.

I chose this specifically over the standard 120MM for the USB3 capability and claimed faster frame rate. However, my testing has turned up an unexpected result.

My laptop has three USB ports. 2 are USB 3 and the third USB 2.

When I plug the camera in the USB ports and have the screen size set to max (1280x960) I get a frame rate of 22.86fps in the USB 3 ports.

The USB2 port returns a rate of 27.82, with all other setting being the same.

How is this possible? What am I missing here?

I have a ton of RAM (16G) on my machine. It is an ASUS 'Republic of Gaming' machine. It has an Intel Core i7 2.6GHz processor, operating at 64 bit.

I also own a 174MM and 224MC and both these cameras perform as expected when plugged in to USB3 Vs USB2. They run much faster in the USB3 ports.

I was hoping for generally faster frame rates and more specifically, better fps under USB3 than USB2.

Any help much appreciated

Sam@ZWO

please confirm:

1.Is the camera recognized as usb3.0 device?

you can tell from the title of FC

2. do you enable "high speed" mode?

3. what is the "usb traffic" setting

mattw

Hi Sam. In reply, in order of your questions:

1. Yes

2. No. High speed mode has not been selected. I had read somewhere this is not a good idea. I forget what the rationale was for this. I'm curious to know why this is optional? Also, what is 'overclock' all about? Does selecting either of these options have an impact on image quality?

3. I have the usb traffic set at 80 for all my cameras.

I am using the cameras under FC 2.4

I also have 2.5.02 Beta, which I haven't checked out fully. It seemed a little 'buggy' the last time I used it. Preview window problems etc

Sam@ZWO

then that is the problem

you need to enable "high speed" to get a faster speed

ASI120MM-S is different from SONY sensors

it still use 12bit ADC in high speed mode

and there is a "over clock" to speed up more

but too fast may affect the image quanlity

mattw

Hi Sam

Thanks for the reply. I selected high speed and that has improved the fps.

I have to say, though, that it strikes me as odd that one should need to do this when the entire reason for buying the camera, over the standard 120MM, is for the faster frame rate via USB3.

It seems odd that it doesn't deliver the faster frame rate by default, rather than having to select it. I bought it for the speed, to work with my USB 3 machine!!!

Many thanks

Matt

Sam@ZWO

MattW wrote:
Hi Sam

Thanks for the reply. I selected high speed and that has improved the fps.

I have to say, though, that it strikes me as odd that one should need to do this when the entire reason for buying the camera, over the standard 120MM, is for the faster frame rate via USB3.

It seems odd that it doesn't deliver the faster frame rate by default, rather than having to select it. I bought it for the speed, to work with my USB 3 machine!!!

Many thanks

Matt

thanks for the suggestion, we will change the default value in our next release software