Javik

The list of custom-built machines that work with Geovision cards is nice, but it might also be useful to know what systems people have tried to build but never got working properly. What system builds have you tried that have either never worked from the very beginning, or would always fail in some manner after a few days? With what situations did you have to just give up, pull the capture card, and try building a different system? -Javik

I am looking at buying the GV800-16 card to build a system of my own, and I am trying to figure out what is the most critical factor in being able to record at high resolutions. Do these cards use the system CPU for frame compression, or can the cards do the compression themselves? How involved is the system CPU in DVR operation? Does it mostly just shuffle data from capture-card to disk, or is it intimately involved in the compression process? When buying a 16-camera card, is it realistic to be able to record at the maximum rated framerate AND use a high resolution like 640x480? Or does upping the resolution from 320x240 to 640x480 suddenly cut the card's 120fps framerate down to about one-quarter (30fps) of the advertised speed? Since 640x480 is four times the areal size of 320x240, does this capture size also cut your maximum recording time down to one quarter of the 320x240 capacity? -Javik

It's been almost a year and a half since this was last discussed. Has anything changed in that time? Is the latest version multithreaded yet? With some single-threaded software, sometimes the dual-core performance is actually worse than with a single core, because the old single-threaded software doesn't know what to do with the multiple cores. For single-threaded programs that exhibit this problem, if you use the Win 2000/XP Windows Task Manager to assign the software to just a single CPU, then the suddenly performance goes way up. (Right click and choose Set Affinity.) (Before the Second Life game client was rewritten to be multithreaded, it would normally start up running poorly at about 15 fps on a dual core system, but when assigned to run on one CPU only, it would shoot up to 60+ fps.) By going through the Task Manager process list and hand-setting affinity for all processes, you can assign only the Geovision app to one of the CPUs, and restrict everything else to the other CPUs, so that the Geovision app always gets one of the CPUs all to itself regardless of whatever else the server is doing. (This setting is not kept through a reboot, though.) If the Geovision software still is not multithreaded, has anyone experimented with setting affinity like this, to see if it improves capture performance? -Javik