Unidentified bug causes massive CPU spike on 27-inch iMacs
Owners of the recently introduced 27-inch iMac have encountered an unidentified bug that reportedly causes massive spikes in CPU usage.
"I just upgraded my 24-inch iMac to the new 27-inch iMacs that just came out. Well, now EVERY Flash-based site like YouTube or Hulu runs unbelievably slow," a user named Subcide wrote on the Apple forum. "Looking at activity monitor, Flash is hitting about 100-110 percent of my CPU. It basically makes the browser unresponsive and the video is choppy."
Forum participant PenSilveltMEKY reported similar performance issues.
"I got my 27-iMac and I realized it [has] performance issues. If you leave it on for more than 5 hours, some applications like Rosetta Stone, Front-Row, iPhoto, Garage band and others start running slowly. I always end up having to restart the system," complained PenSilveltMEKY. "And this morning I encountered the Flash problem, I had to download the video I was watching on the Internet before I could finish it. Not cool at all. This is not a VISTA. IS IT?"
Another iMac owner emphasized that CPU spikes were not limited to Flash-based applications.
"I'm having the same slowness issues even if I don't play any Flash video," claimed GizaDog. "Firefox starts using all the CPU's power (100 percent) from one core. Doing anything within the browser creeps and is very sluggish. The only why I found to temporary resolve the issue is to either restart or have the system sleep by pushing the power button."
Unsurprisingly, frustrated iMac owners have suggested a number of unofficial and temporary fixes, including power cycling Apple's AirPort, triggering the iMac's sleep\wake cycle, resetting PRAM\NVRAM and re-installing Snow Leopard.
However, a user named Rhyceudique clarified that the above-mentioned fixes were only "temporary."
"The problem will return. I opened a case with Apple and they say it may be a video card issue. I'm awaiting a fix," added Rhyceudique.