All modern computers (e.g. dual-core and better) based on Intel, AMD and Nvidia chipsets have two high-speed USB (USB 2.0) controllers on board. That should give you enough bandwidth to be able to record with:
- 2 depth sensors (MS Kinect, or ASUS Xtion, or PrimeSense Carmine)
- or 4 cameras at 640x480 (raw Bayer format) at 60 FPS
- or 6 cameras at 640x480 (raw Bayer format) at 40 FPS.
You can check how many USB 2.0 controllers you have in the “Universal Serial Bus controllers” section in Device Manager. Operating system will display USB 2.0 controllers as “USB Enhanced Host Controllers” (not to be mistaken with USB 1.0 “USB Universal Host controllers”).
You should make sure that you have depth sensors or cameras evenly distributed between available USB 2.0 controllers. For example, if you have 4 cameras, you should connect 2 cameras to first controller and 2 cameras to second controller. Device Manager usually shows USB cameras as “USB Composite Device” at the “Advanced” tab of USB controller properties. If you have too many cameras connected to single USB 2.0 controller, you should re-plug them to different USB ports.
If several devices are connected on the USB hub and working in parallel, then the USB bandwidth is shared among the devices. Connecting all cameras via single USB 2.0 hub is OK only for low resolution video recording (320x240). To be able to record video at 640x480 and 60 frames per second, you should avoid connecting more than 2 cameras via single USB controller.
Potential issues with USB controllers
Some USB chips have compatibility issues with specific cameras which may result in not detecting cameras, low frame rate, etc. See the next section on known issues.
Many modern laptops have one of the integrated USB 2.0 controllers reserved for docking station. That may effectively halve your USB bandwidth. So laptops with a large number of USB ports (4 or more) are preferrable. Desktop PCs should not have such problem.
Important. Before buying a specific laptop model it is strongly recommended to ensure it has the sufficient number of available built-in USB controllers and they are compatibile with cameras you intend to use. Find it at your local retailer, and bring cameras with you to test. Though it may be easier if your friend/neighbour has such a laptop. Or ask at our forum, maybe someone already used this model with our software or can recommend specific model for your camera configuration.
If you plan getting an additional USB controller, please be aware of potential problems with USB 2.0 controllers available on the market. Many USB 2.0 controllers are based on defective NEC USB 2.0 chip, not capable of standard USB 2.0 speeds. That's a well-known bug specific only to NEC USB 2.0 chip. By contrast, all NEC USB 3.0 chips are good and do not have this problem.
Some manufacturers sell what they call a "USB 2.0 ExpressCard" controller for laptops. Many of such ExpressCard controllers are in fact internal USB hubs in ExpressCard form factor. That means they do not add actual USB bandwidth to the system. All USB 3.0 ExpressCard are controllers.
If you plan getting additional high-speed USB controller, we strongly recommend that you get a USB 3.0 controller, just to be on the safe side.
When setting up a USB 3.0 controller, make sure you configure it to handle USB 2.0 traffic (as opposed to passing USB 2.0 to integrated USB 2.0 controllers in your chipset). There should be a corresponding setting in driver properties or in BIOS.
Known compatibility issues
Combinations of camera & USB chip listed below have known compatibility issues. Unfortunately, there is no guarantee that other combinations will work for sure, but most will. If you need an additional USB controller for connecting specific camera, be sure not to get the one based on incompatible USB chip.
|Camera||USB chip||Symptoms||Comments / possible solution|
|ASUS Xtion (Live)||NEC µPD720200 (USB3)||Camera is not properly recognized by the system.||This firmware update makes device behave the same as PrimeSense Carmine 1.08 with this controller.|
|ASUS Xtion (Live)||VIA VT6212L (USB2)||Frame drops of color picture in 640x480@30 (depth + color).|
|PrimeSense Carmine 1.08||NEC µPD720200 (USB3)||Frame drops in 640x480@30 (depth + color).||Stable work in 640x480@30 (depth only) and 320x240 (depth + color).|
|PrimeSense Carmine 1.08||VIA VT6212L (USB2)||Frame drops in 640x480@30 (depth + color).||Stable work in 640x480@30 (depth only) and 320x240 (depth + color).|
|PrimeSense Carmine 1.08||VIA VL800(USB3)||Frame drops, reduced frame rate, freezes in depth + color modes.||Stable work in depth only modes.|
|Sony Playstation Eye||VIA VL800 (USB3)||Great number of bad frames and frame drops. Camera is invisible to iPi Recorder.|
|Sony Playstation Eye||VIA VT6212L (USB2)||Great number of frame drop in 640x480@60 mode.||2 cameras can work smoothly at lower FPS (up to 640x480@50).|