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Post by Deleted on Jun 29, 2014 23:18:07 GMT
Hi,
With more and more USB 3.0 based cameras coming onto the market, here is a very useful guide provided by Point Grey in Canada, which I think sums it up very well and I thought it worth sharing with you. It is a .pdf file. It shares 5 key points in a very easy to understand concise way.
www.ptgrey.com/support/downloads/documents/USB3_Top5.pdf
Clear skies, Shevill
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Post by Dragon Man on Jun 30, 2014 5:51:26 GMT
Thank you Shevill. With an ever increasing range of USB 3 peripherals we need all the information we can get to take advantage of it.
I was reading in another Forum that some people were running USB 3 devices but they ran like they were on USB 2 speed. When given a few settings to use they said it was like they had a new powerful computer.
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Post by Deleted on Jun 30, 2014 6:00:13 GMT
Thanks Shevill, and any useful info you find Ken, would be useful to post here.
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Post by Deleted on Jun 30, 2014 7:18:38 GMT
Hi,
With more and more USB 3.0 based cameras coming onto the market, here is a very useful guide provided by Point Grey in Canada, which I think sums it up very well and I thought it worth sharing with you. It is a .pdf file. It shares 5 key points in a very easy to understand concise way.
www.ptgrey.com/support/downloads/documents/USB3_Top5.pdf
Clear skies, Shevill Thanks Shevill,
Very useful information. I did try the USB3 route with Blackmagic but with no success though this is still something I'm hoping to work out for the future. From what I have gathered so far my own USB3 ports are not real USB3 and nor is my PC anywhere near powerful enough so next stop for me before any new camera is a new PC!
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Post by Deleted on Jul 9, 2014 14:17:06 GMT
All of the INTEL 3rd generation (Ivybridge) and 4th generation (haswell) based PCs support USB 3.0 including the xHCI host controller which provides the DMA and port polling in the controller so that the system doesn, get involved with these time consuming functions. Also USB 3.0 compliant connectors and cables have a USB 2.0 hardware connection as well as a USB 3.0 connection which means that you can plug a USB 2.0 cable in and it will work fine, but it also means that if a USB 3.0 device is having trouble with the 3.0 connection it will fall back to 2.0 to maintain the connection. The document is dead-on about using PCIe host controllers and the speed of the PCIe bus lanes with respect to Bus revision I don't know much about AMDs architecture but Intel has not put out a PCIe bus lower than 2.0 (500MB/s per lane ) in at least 3 years.
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Post by johnno on Jul 9, 2014 22:16:38 GMT
Thanks Shevill for the info, for once i could understand most of it. Only this evening i found that my usb port on my laptop is only putting out 400ma, i don't know if this is the cause of low fps and temporary freezing.
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Post by Deleted on Jul 10, 2014 0:08:56 GMT
Thanks Shevill for the info, for once i could understand most of it. Only this evening i found that my usb port on my laptop is only putting out 400ma, i don't know if this is the cause of low fps and temporary freezing. Hi John,
If you are running on just the laptop battery, you will have limited power available at your USB 2.0, 3.0 ports, simply because the laptop itself needs a fair whack to keep running and doing its tasks. Try plugging in its main power source and see if that improves things. This is one of the limitations of many laptops with say only 6-cell power packs. I always make sure I have the largest power pack (9-cells) option when buying a laptop, most why I use desktops, which I build myself and if I know it will have lots of things plugged in, I make sure it has a big power supply.
What current does the camera need to run its USB 3.0 camera?
Clear skies... Shevill
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Post by johnno on Jul 10, 2014 1:55:37 GMT
Hi Shevill, its a usb 2.0 PLB-Cx camera and the i5 laptop was running on the mains adapter, cpu load was knocking around 60%, only had the camera software and the broadcast software running and nothing else plugged in.
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Post by Deleted on Jul 10, 2014 6:24:53 GMT
Hi Shevill, its a usb 2.0 PLB-Cx camera and the i5 laptop was running on the mains adapter, cpu load was knocking around 60%, only had the camera software and the broadcast software running and nothing else plugged in.
Hi, Not familiar with that range of cameras so no idea what their current draw is like. I know that when the Meade DSI range came on the market, they were power hungry and many would not work on a battery powered laptop and or a cheap USB cable with limited current carrying capacity. There are just so many variables with laptops and computers in general, it can be very difficult to know where a bottleneck might be. I do know that the more you pay the better spec the box-as with most things electronic!
Clear skies... Shevill
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Post by Deleted on Jul 10, 2014 18:12:32 GMT
Johnno the USB 2.0 spec requires that the host port provide 500ma to the device I am not sure how you are measuring the current but if your camera was trying to draw more current that what's available the camera wouldn't slow down it would probably not work at all because the 5 volts would begin to drop and cause the camera to reset.
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