Electronics

[gardenman]

If I was guessing, I'd guess that there was an issue with the cat 5 cable/jacks. A hardwired connection like you have with the iMac should give you the best performance and instead you're getting the worst performance from it. I'd try unplugging the cable from the router and iMac and then making sure it was in contact with and around as few other cables/cords as possible and reconnect and see if that makes a difference. The cable could be picking up interference since cat 5 cables aren't especially well shielded. If you still get the same performance, try using a different output jack on the router and/or switching cat 5 cables. You're pretty much stuck using the cat 5 port on the motherboard, but if none of that works then borrowing a USB wi-fi dongle to see if that helps might be a good option for you to go wireless on the iMac.

[glb613]

My iMac has built-in Wifi which I have disabled. The reason, the hard wired connection is faster. Next time it happens, I'll switch to Wifi and see if the jerky video continues or not. Thanks everyone.