How many framegrabbers can a regular PCI bus run at the same time?

[Jeffrey01]

I am considering a new machine vision application, and was wondering how many PCI-based framegrabbers, of the type PCI-1411, I can run simultaneously.

I did a "back of the envelope" calculation for 3 framegrabbers each grabbing 8-bit grayscale NTSC video (640x480 res.) at 30 fps that went like this: 307 KB per frame * 30 frames per sec * 3 boards = 27 MB/sec. To me this seems pretty close to the PCI bus speed of 33 MHz. But I am not a computer engineer so I am not sure (I am not even 100% confident I have the bus speed correct).

Anyway, maybe there are other customers or applications in which multiple framegrabbers were run at the same time? I mentioned 8-bit images above and that is fine, but I would really prefer RGB color. Also, my target card count is three.

[Steffen Hoog]

In my opinion the max bandwidth is 132 MByte. I think you can use approx. 90 MByte/sec. But be careful. This bandwidth will be shared by all components (not the grabber only).
Did you heard about the NI-PCIe-1430? This is a dual base camera link frame grabber. Means you can connect and aquire from two camera link cameras at the same time. The 4x PCIe bus has got a bandwidth of 4x 250 MByte/sec. In this case the botleneck is camera link (680 MByte/sec). But 680 MByte/sec should be enough, right? To aquire images from the third camera you can use the PCI-1426. Also a base camera link grabber. But only for one camera not for two.