[Macpilot]

Hello guys.

I have a 15" Powerbook with 128 VRAM, hooked up to a 20" Cinema Display.

I have noticed that with about 10 apps running, and roughly 10-15 windows open in Display Spanning mode, the fan in the Powerbook will come on intermittently. Sometimes it will run for several minutes.

This fan behavior does not occur when the Cinema Display is not hooked up. I am assuming it is normal.

I have checked the Activity Monitor for an offending app that might be causing the CPU usage to be so high to turn the fan on. There is none. The "WindowServer" process is usually at the top of the list in terms of CPU usage.

When I just returned to the computer, the screen saver was running on both screens and the fan was on. When I awoke the desktop, after a minute or so, the fan went off, but I quickly checked the Activity Monitor and is was showing around 15% CPU for the "WindowServer".

Do any of you have similar behavior with Powerbooks and external displays?

[Dr.Michael]

Originally posted by Macpilot:

Do any of you have similar behavior with Powerbooks and external displays?

Yes, thats normal. The video chip has much more work to do and produces the additional heat.

[free lunch]

I run my 12" in clam shell mode hooked up to a Dell 20" FP display at work. The fan is on almost constantly. So what you're experiencing makes sense and seems pretty normal.

Interestingly enough, M$ and Adobe apps (Excel, Acrobat!) seem to keep the fan humming even more when used in this config, just by nature of them being open, ie. just the apps without documents. Hmmm...