Excessive fan noise when iChatting?

Question

Usually when engaged in multi-party iChat, the fan comes on and makes the audio spotty and/or just causes disruptive background noise.  Does anyone know why?  What can I do to stop it?

Answer 1

HI,
You could try limiting the bandwidth in iChat.
iChat Menu > Preferences > Video section > Bandwidth Limit drop down.
Set this to 500kbps
It has several outcomes.
1) the Bandwidth os capped and this can smooth out some video with Buddies where the speed of internet is massively different.
2) It can help if the ISP varies the service a lot
3) 500kbps is higher than the listed 384kbops Minimum (UP and Download) for 4 way Video Chats
Limiting this to this level will reduce the need to fill the Bandwidth (It's a rough description of what iChat does - it grabs a much as it can, within some limits) and works at a lower rate.
You can notice this in the Connection Doctor (Video Menu) during a  live Chat.
The Bandwidth will be reported as less which will also tend to reduce the Frame Rate  (if your upload is higher then the 500kbps).
The less the computer has to work at producing Video the lower the processor has to work.
At certain points which you cannot control, directly iChat will reduce the number of pixels in a  frame  which also reduces the load (However, strangely, you may see your Frame Rate go up as the Computer can produce smaller pics/Frames more quickly).
The Max pic size is 640 X 480 in iChat 2 through 5  (4:3 ratio)  (0.3Mp)
The next size down  is 480 X 320
In Lion  (iChat 6) you are using a HD camera at 16:9 ratio
At the highest setting iChat can manage this is in excess of 1.3Mp to a frame.
Also don't play Host.
Allow rthe person with the fastest Connection Upload and download be Host.
It can also help if all parties use the same Bandwidth Limit.
Some very fast can send you data faster than iChat  and your service can deal with it.
This cause iChat extra work as it drop frames and tries to keep the Audio in Sync.
At certain points it cannot manage the Audio Sync and it will drop the Audio.
It has always done this since iChat 2 but was less noticeable due to a Limit in Quicktime Settings and being 1-1 chats.
10:16 PM      Saturday; June 30, 2012
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