ASI120MC-S FPS for USB 3.0 vs USB 2.0

topboxman

Hello,

My first post here. I have been a long time DSO imager and would like to try out planetary imaging. I bought ASI120MC-S camera and I tested it indoors with FireCapture and it works well. I am glad it came with All-Sky lens so I can test it indoors.

The camera came with USB 3.0 cable so I plugged the cable into USB 3.0 port of my computer and FireCapture detected the camera as a USB 3.0 camera. The fastest frame rate I could get was about 22-23 FPS at maximum resolution according to latest and greatest FireCapture 2.4.10.

Then I use USB 2.0 cable and use USB 2.0 port of my computer and ran the same test and got almost 30 FPS.

Can anyone tell me what this means? Is it a bug in FireCapture or did I get a wimpy USB 3.0 cable?

I have not yet use the new camera under the dark sky because it has been cloudy due to "new scope/equipment curse".

Thanks,

Peter

riklaunim

HDD speed may limit recording speed.

topboxman

OK, but why would frame rate for USB 3.0 be slower than USB 2.0? I would expect USB 3.0 to be the same or faster.

Thanks,

Peter

draconis

The cable itself will have no effect on your transmition rate . 2.0 is limited by the bus in your computer . To get the full 300 mps you will need a 3.0 with an appropriate bus in your pc . Even adding a pce card for 3.0 only gives you 70 mbps .To truly get the speed your camera is capable of you need fully functional bus +3.0 + ssd to record on .\

Most any newer pc/laptops will have this functionality from lower to extreme end . If the hdd is 7200 or lower (non ssd) use an external ssd for capture and manipulate files from there . You will have to be 3.0 from the bus for this to work .

You do not really need a 'monster' pc to make this work anymore .You would benefit from an i7 type quad core and ability to upgrade ram to say 16 gigs .

This would give you total functionality with your camera .

You can meet this criteria with a fairly modestly priced laptop today compared to just a few years ago .

as a side note , if you are a 'file horder' on a budget I would suggest any economical storage devise to transfer files to save to . The ssd is meant to be a high speed working devise and not to save files on .

topboxman

I don't think both of you are understanding what I am trying to say.

I have a bleeding edge PC with i7 Quad Core and 16GB RAM and it has several USB 3.0 ports. My ASI120MC-S is a USB 3.0 camera.

But never mind that. My question is:

WHY DOES FIRECAPTURE DISPLAY SLOWER FRAME RATE (22-23 FPS) USING PC's USB 3.0 PORTS THAN USB 2.0 PORTS (~30 FPS) FOR EXACT SAME SETUP (same gain, exposure, etc.)??????

If I knew this, I would have saved $100 by buying a USB 2.0 version camera.

I am not complaining about not reaching full potential of USB 3.0 specification. I am complaining about why the FireCapture is displaying a slower frame rate using PC's USB 3.0 port (yes, I am using USB 3.0 cable) than using PC's USB 2.0 port (and USB 2.0 cable) using a USB 3.0 ASI120MC-S camera, this makes no sense unless there is a bug in FireCapture software not handling USB 3.0 correctly.

Peter

riklaunim

Well, ASI cameras do have some firmware issues sometimes ;) You will have to wait for Sam from ZWO to reply on this.

Also check "USB Traffic" in FireCapture. If it's low try maxing it out.

topboxman

I figured it out. There is a "High Speed" check box in FireCapture and I checked it and finally the frame rate doubled (60 FPS) for USB 3.0.

Thanks,

Peter

xs_man

Maybe 2 or 3 suggestions to try : ;)

- Do you have access to another PC to make some tests ?

- Your version of Firecapture may be too old and do not support correctly USB 3.0.

Try to update it or download last version.

- Slow hard disk, 5600 rpm for example. Best is to have a SSD disk but a

good 7200 rpm should be enough.

- Power feeding through USB 3.0 may be limited, especially on Portable PC,

and decrease framerate could be a result,

- Are the USB 3.0 ports on separated electronic card or directly on motherboard ?

A bad chipset for USB 3.0 could give a low framerate.

- With 16 GB, you can use 'RAM buffer' in Firecapture and adjust to max, it

greatly increase framerate.

Sorry, I see that you have find the solution !

Albéric