i get almost 8 dv movies at 25fps with a quad g5 - and a single fujitsu MAU 3147 scsi drive.

if you reduce the image size to 512x512 or 640x480 - or even 384x288 for playing back with pixelmad - or lower resolution video walls- you can get upto 15 movies at 25fps at the same time using photojpeg 50-60%