some things that made me sad when reading this github: > One USB Host can theoretically take up to 127 client, but we found out only 1-2 Cameras per host contr

some things that made me sad when reading this github: > One USB Host can theoretically take up to 127 client, but we found out only 1-2 Cameras per host controller work without glitches and missing frames. and you didnt realize what is the real reason (not the limit of 7 bits address field in USB protocol)? No one bothered to do a simple calculation 640x480x2x30 per camera? :( btw USB 2.0 in reality is able to sustain ~40MB/s, hence 2 cameras at 30Hz max per controller = ~37MB/s. >PCI can process less data then PCIExpress, so it is best to build your system on PCIe cards PCI is ~130MB/s, plenty for 6 cameras, again no numbers Of course you could simply find cheap cameras with building mjpeg compression and avoid adding external usb controller cards - Great source for cheap camera modules is laptop service parts. For the last 10 years USB webcams have been standard in laptops. Example ebay auction http://www.ebay.com/itm/Macbook-iSight-Camera-replacement-for-A1342-/381214713303 http://www.ebay.com/itm/Macbook-iSight-Camera-replacement-fo... ISight supports: MJPEG 640×480 @ up to 60fps MJPEG 720×480 @ up to 60fps MJPEG 800×600 @ up to 30fps MJPEG 1024×576 @ up to 30fps etc ... and all of a sudden we have <3MB/s per $3 camera.