Testing a Altair IMX 224 hypercam frame rates

[neil phillips]

As I mentioned on the deepsky thread, I would test frame rates of the ASI 290MM against Altairs IMX 224 chipped USB3 camera  One may wonder 

why I am comparing two completely different chipsets. Firstly I do not have a ZWO 224 Here. Or for that matter a Altair 290 mm which hasn't been produced yet, as far as I am aware. So to test how good the Altair is performing, I can only go by what cameras, and I might add laptops I have to hand. Personally I do not particularly like the idea of a very expensive SSD drive, wearing out over time. Even though performance is better. But you pays your money you make your choice. The test itself was a rather interesting one. And certain things quickly came to light. Namely the high speed setting on sharpcap was helping the frame rates of the zwo camera enormously. But if its helping, its helping right. Not in everyway. I have found the signal purity, to be effected using the high speed setting on both sharpcap and firecapture. In my case line noise appearing much stronger in high speed mode. Infact my zwo camera has this line pattern noise on USB3 3 period. which worsens upon high speed acquisition. On USB 2 it completely disappears ? Now whether this pattern noise will show in any situation is up for debate. But according to ZWO it will not. A I was told they get it too. But others have said to me they do not get it period, make of that what you will. So far I have been shooting in USB2 mode in situations were there was no advantage in using USB3. But that will change at some point. And I guess then I can compare. But I suspect it will stack out. Here is a example. There is no noise on the Altair USB3 captures.  I will get to frame rates in a second  

USB3 HIGH SPEED

USB2 NO HIGH SPEED

Ok back to frame rates after that is clarified. Viewers must bear in mind that ZWOs own version of the Hypercam, but without fan, namely the ASI224MC when one compares the frame rates from there own specs against the ASI290mm they are considerably slower example 640x480 299.4 FPS for the ASI 224 and 381.2 FPS for the ASI 290mm this frame rate advantage runs through the entire resolutions. increasing in advantage the smaller the box size becomes. By the time we are at small sizes namely 320 x 240 we are at 577.9 FPS for the 224 MC, and 737.5 FPS for the 290 mm

So its clear the 290mm is faster than there own 224MC This should be considered when the figures I produce here in the real world, with a non SSD laptop or drive. Are shown

Ok the figures.  I tested the hypercam on its own software, and ZWO 290 on sharpcap. previous tests by me showed if anything sharpcap may have a been a tad quicker than firecapture. But results were similar. So I saw no advantage in using firecapture for these tests. And considering its a unfair advantage anyway for the ASI 290MM against the Altair hypercam. As from their own figures of their own two cameras. lets not split hairs.

Hypercam Altair software 1280x960 = 8864 Frames in two minutes

ZWO 290mm sharpcap 1280x960 = 8851 Frames in two minuets

ZWO 290mm 1280x960 Noiser high speed mode = 9026 Frames in two minuets

 

Hypercam Altair software 640x480 = 27949 Frames in two minuets

ZWO 290mm Sharpcap 640x480 = 21906 Frames in two minuets

ZWO 290mm 640x480 Noiser High speed mode = 34676 Frames in two minuets

 

Hypercam Altair software 320x240 = 52328 Frames in two minuets

ZWO 290mm Shapcap 320x240 =42736 frames in two minuets

ZWO 290mm 320x240 noiser high speed mode = 87761 Frames in two minuets

Clearly the ZWO is getting its advantage over the hypercam with high speed mode on. Without it the Hypercam wins on all counts. The only reason this wouldn't matter. Is if the purity of the signal was the same. Which clearly it is not from my examples here. The examples are not just high speed off and on. But USB2 Against USB3 input, as the lines are still apparent without high speed mode switched on ? They seem to get drawn out wider when high speed is switched on. This happens in both sharpcap and firecapture. How much this purity will affect anything in the real world is up for debate. But according to ZWO it will not. Indeed I belive they might be right. But I will say this, I am not certain of this. And any situations were USB3 is not needed I will be certainly using usb 2 for a purer signal. why would I not. The other eye opener is when high speed mode is switched on the smallest box size i tested. namely 320x 240 here its advantage jumped enormously. These figures are only from this particular laptop. Clearly completely different results might be got with other machines. Especially SSD If anyone wants to know the specs of my laptop just ask away.

[Ewan]

Interesting post there Neil.

I mainly do solar now although I will have to have a crack at planets again once I have dug the C8 out again.

I was looking for a high speed camera to go with my solar rig, opted for a USB 3 PG IMX174, to be able to capture huge amounts of frames I needed something that could shift, I found using the IMX174 with a mechanical hard drive was next to useless, the frame rates were no where I expected they should be.

Having invested in a Samsung EVO top end SSD drive the camera never drops any frames & works to the maximum possible, the capture rates are stunning even in 16Bit mode. I for one can see the benefit of USB 3 over USB 2.

Although my camera is not any of yours above it's an interesting point of USB 3 over USB 2 not just speed but in, as you say, the signals purity, I may have to try my 174 on the USB 2 port just to see how it pans out.

With high Gain values & max frame rates on USB 3 the lack of any noise in the captures is amazing, I am pretty sure after seeing how good USB 3 I could not go back to 2.

Do the cameras you use run off the USB power source ?   I am wondering if a dedicated power source for the cameras might yield a cleaner signal ?

My laptop is not particularly advanced as it's an i3 but adding more RAM to 16Gb did help with the capture buffers, they just don't fill up.

Atb

Ewan

[neil phillips]

Hi Ewan. yes of course performance of SSD is not in question. Though I would worry about longevity a little.

Yes the cameras do run off USB. interesting idea about a separate power source. Any idea about those. I don't know much about that. What devices are out there ect.  My laptop is also i3 though only 8gig ram

[ChrisLX200]

I wouldn't worry about logevity of SSDs, and there are things you can do minimise the effects of repeated re-writes (with Samsung drives anyway, their 'Magician' utility will set aside an area which acts as an intermediate buffer). A traditional HD is likely to fail due to some other fault long before your SSD will die from excessive re-writes, and disks (SSD or HD) should be considered as consumables At full resolution my ASI178MM streams at just over 30fps onto an SSD, much higher frame rates achievable if you use a cropped frame of course.

In your images above I have never noticed the line noise you show with USB3 high speed, perhaps it's not just the camera but the computer that contributes to this? I use an i7 with 32GB RAM which is also water-cooled and over-clocked so there's plenty of processing power available.

ChrisH

[neil phillips]

1 hour ago, ChrisLX200 said:

I wouldn't worry about logevity of SSDs, and there are things you can do minimise the effects of repeated re-writes (with Samsung drives anyway, their 'Magician' utility will set aside an area which acts as an intermediate buffer). A traditional HD is likely to fail due to some other fault long before your SSD will die from excessive re-writes, and disks (SSD or HD) should be considered as consumables At full resolution my ASI178MM streams at just over 30fps onto an SSD, much higher frame rates achievable if you use a cropped frame of course.

In your images above I have never noticed the line noise you show with USB3 high speed, perhaps it's not just the camera but the computer that contributes to this? I use an i7 with 32GB RAM which is also water-cooled and over-clocked so there's plenty of processing power available.

ChrisH

Its interesting Chris to hear others views on SSDs. I don't have any experience just different things I have read from different sources. I agree with the computer idea on the line noise. Though I don't quite understand why the IMX 224 USB 3 has none of it ?

I just remembered I showed this to Sam of ZWO who said I have it too. and showed me a screen shot at high gain with lines Chris. maybe some 290 chips have it more than others.  And other chips have none . But I can only say what happened when I contacted Sam. Its weird. What I didn't ask Sam is do the lines he was showing me go away on USB2 as my example here ?