Why is Safari using 91% of a CPU when it's in the background!?!

[Moof1904]

WTF? Why is Safari using 91% according to the Activity Monitor and to top it off, Safari has only one window open and it's in the background?!?!? (The one window, btw, was Mac Rumors.)

 

[hawaiian]

Good question. My best guess is that Safari is using 91% of the processing power that is being used at that moment, not 91% of total available processing power. You might be able to verify that.

 

[jczubach]

WTF? Why is Safari using 91% according to the Activity Monitor and to top it off, Safari has only one window open and it's in the background?!?!? (The one window, btw, was Mac Rumors.)

that seems insanely high, here's mine. Have you tried restarting safari?

 

[Moof1904]

Now it's back down to 0.2%. Bizarre!

 

[MK2007]

How long was it at 91%? When you doing nothing Safari should be at 0.00%.

 

[Eidorian]

1. Is it page loading?
2. Flash

 

[Moof1904]

It was in the background while I was away from the computer. I returned to hear my fans running (Dual 2.5 G5), launched Activity Monitor and saw that Safari, sitting idle in the background on the MacRumors Forums page (no other windows open) was running at 91%. I started this thread, posted the thread, and when I next looked, Safari was behaving itself again. I look while I'm typing this and it's occasionally jumping up to 6% or 7%, but nothing unreasonable.