Multi camera acquisition frame rate drop

[AeroROACH]

I've a project at my university that have to get the acquisition frame rate at 100fps with 3 cameras at the same time.

At first I use Vision module to get acquisition .avi file on single camera and it works fine.

I use grab method with IMAQDX to acquisition picture.

It can reach 100fps without any problems (resolution of picture is 640 X 480).

Then I start to use 2 cameras. It's seem like frame rate a little unstable but I can accept with this situation.

Finally I get to my goal at 3 cameras at the same time. The problem occur in this state.

Frame rate drop down around 50fps. Even if I try to reduce resolution to 320 X 240 it can just reach around 70 fps.

I don't have a clue about root cause of this problem. Could you please give me some suggestion to solve this problem.

My computer spec is :

CPU : Intel Core I5 2.7 Ghz

Ram : 4GB

OS : Windows 7 64 bit

Camera : all 3 cameras as you see in attach file interface with GigE card.

Sorry for my poor english.

Thank you for your help.

[falkpl]

Do you have 3 seperate gigE ports or are you using a switch?

what is your architecture, do you have seperate loops, are you processing or displaying the images in this loop?

is the camera 8-bit or color?

You can start with a bandwidth calculation - 640*480*100*8 = 245 Mbits (adduming 8-bit cameras) and GigE doenst get the full 1000MB, there is always packet overhead.  you might do best with a 4port card but its too early in the morning for me to think this out fully.