How many usb2 cards possible? 1

[polio]

I`m working with webcams, (but not for the web) and have to plug as many USB cams as possible into a Pc. Because of the USB2 bandwitch, each usb card can handle only to webcams, even if more slots. So I wonder how to calculate, how powerful prosessor, how powerful ram etc, that I need for, example 6 USB2 cards, or 10 cards, 20, 30 cards.
Or how many Pc`s do I need (pc`s then for example; small processor small ram, minimum harddisk,- no grafics card???)???. How weak can the pc`s be and still handle the videostream, based on them only being a source reciever wich then later transfers to one mother pc. And is it at all possible?

I know this might be a very specific problem, but mabye I`ll be lucky and there`s a genious geek out there who might just have almost the right answer.

I hope, I hope..

 

[polio]

Ok, I got some answers to my own problems..
An average up to date pc, can handle almost unlimityed amount of USB2 cards. But. There is no maincard (bad english?) with slots for more than 5 usb cards, and it is not possible with multiple maincards for one set of, processor, ram etc. OR IS IT?

 

[Frank4d]

If I remember correctly you can have up to 256 USB nodes so that shouldn't be an problem. There are known issues with having multilple USB devices that are exactly the same, so you need to make sure any software that comes with them can deal with it (do the USB webcams send their serial number)?

I design systems for work and have experience with putting 25 cards in one PC... so I know it can be done. How many webcams do you need to connect? What video resolution? Frames per second? Capture all at once or time multiplexed? Is writing your own software an option?

 

[Frank4d]

Look at

http://adlinktech.com

single board computers and passive backplanes. You can get dual Xeon P4s that take 4GB RAM and 18 slot backplanes. If you are in western USA I can give you contact information.

Another option is multiple computers connected together via reflective memory or fiber-channel if real-time is important, or TCP/IP.

 

[polio]

Thanx for a most helpful reply..

I`m an video artist. The problem with multiple identical cameras I know of. Waiting for reply from Logitech, conserning possible tweak of the driver. But I know specific brands of webcams without this problem ( ex. Logitech QuickCam communicate STX pro4000). I`ve got almost finished Max- Jitter software now, wich does exactly what I want, wich is:

Realtime streaming of all videosorces (the few I have now). Minimum 25fps. Live footage is to be sendt over web to a closed web source, type conferance. Resoloution will be in large scale with "reasonable" quality. The stream over internet I consider one or several industrial lines -(collected footage out, or split up wich gets assembled by reciever). (Ok I told you it wasn`t for web, but thats secondary problem).

The single board computers and passive backplanes, seem very interesting. Have I understood it right? A pc without motherboard, designed firstly for telephone companies?? Multiple connected computers, is as you say an easy option.

 

[polio]

Oh, I live in Scandinavia, by the way...

 

[polio]

I`ve been checking around, both surfing the web and with qurious eager local retailers. This computers you speak of; single board computers and passive backplanes seems to be serious industrial computers. Not easy accessible on the regular market. My question IS: Is it possible to run windows/Mac based programs on such an coputer. I`m not an programmer, and for this project I need to run a Max-MSP-Jitter based program. This software doesn`t support Linux platforms. Will this be a problem?