I've heard this on every computer I've owned, going back 14 years to my Apple IIgs. Any CPU operation (tight loops reading memory especially) could be heard as pitched tones on the audio out, especially noticable when listening with headphones. On the IIgs, I had a stereo "Audio Animator" card and always figured it was crappy RF shielding. You could hear a scale, tones changing as you moused over each item in a menu.
But it happens on my other computers too, to larger or smaller degrees. On my TiBook, it's pretty noticable when the fan/drive are spun down. I program in Cocoa/GL and you can hear the tone change just by creating an NSTimer with different frequencies, and using it to do graphical operations. Most of the time, this results in a low 60Hz "hum."
I think it's due to RF interference between the audio portion of the board and whatever else is nearby. It seems more prevalent on laptops where everything is packed closely together but it's not limited to laptops, or LCDs.
Somebody should write an app that plays one-channel melodies with the RF noise...;)
10.2.4 includes new ATI Radeon drivers (v 1.2.12.11) but they don't fix vbl-sync in windows which 10.2.3 broke. This is really awful, every operation (dragging windows, scrolling, quicktime, etc etc) exhibits noticable tearing and gives me a headache.
I can't understand why Apple/ATI did not fix this, every version of OS X UP TO 10.2.2 syncs to VBL perfectly, how can they ignore this?!
After upgrading my 800Mhz TiBook to 10.2.3, everything drawn on screen exhibits tearing. Dragging windows, flipping between menus, scrolling (horizontally...) and most importantly the little apps I am working on.
It looks to me like they turned off the WindowManager's sync-to-VBL for all window flushes. This is different than every previous version of OS X.
Now, this isn't a critical bug, nobody is losing any data from it. But it LOOKS HORRIBLE. I know I am going to get a headache from this in the next few days. And forget about developing anything with smooth animation (in a window. Full screen contexts still appear to work.) I wish I could downgrade to 10.2.2.
I'd run over to the Apple Store to see if it's just my machine or what, but being located inside the mall I'm hesitant to go anywhere near it until after New Year's.
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I've heard this on every computer I've owned, going back 14 years to my Apple IIgs. Any CPU operation (tight loops reading memory especially) could be heard as pitched tones on the audio out, especially noticable when listening with headphones. On the IIgs, I had a stereo "Audio Animator" card and always figured it was crappy RF shielding. You could hear a scale, tones changing as you moused over each item in a menu.
;)
But it happens on my other computers too, to larger or smaller degrees. On my TiBook, it's pretty noticable when the fan/drive are spun down. I program in Cocoa/GL and you can hear the tone change just by creating an NSTimer with different frequencies, and using it to do graphical operations. Most of the time, this results in a low 60Hz "hum."
I think it's due to RF interference between the audio portion of the board and whatever else is nearby. It seems more prevalent on laptops where everything is packed closely together but it's not limited to laptops, or LCDs.
Somebody should write an app that plays one-channel melodies with the RF noise...
Well, I'm not sure about the 7000. And it probably won't occur on any PCI card since I think it only QE-capable (i.e. AGP) cards are affected.
But it does happen on:
Radeon 7500 Mobility
Radeon 9000 Mobility
Radeon 9000 Pro
i.e. all the current ATI chips in the Apple store.
The easiest way to see it is to just Zoom In via Universal Access and move the mouse around. Constant, impossible-to-miss tearing.
10.2.4 includes new ATI Radeon drivers (v 1.2.12.11) but they don't fix vbl-sync in windows which 10.2.3 broke. This is really awful, every operation (dragging windows, scrolling, quicktime, etc etc) exhibits noticable tearing and gives me a headache.
I can't understand why Apple/ATI did not fix this, every version of OS X UP TO 10.2.2 syncs to VBL perfectly, how can they ignore this?!
iPhoto includes two .mp3s in it's bundle:
iPhoto/Contents/Resources/Music/Jesu, Joy Of Man's Desiring.mp3 (3 MB)
iPhoto/Contents/Resources/Music/Minuet in G.mp3 (1.7 MB)
After upgrading my 800Mhz TiBook to 10.2.3, everything drawn on screen exhibits tearing. Dragging windows, flipping between menus, scrolling (horizontally...) and most importantly the little apps I am working on.
It looks to me like they turned off the WindowManager's sync-to-VBL for all window flushes. This is different than every previous version of OS X.
Now, this isn't a critical bug, nobody is losing any data from it. But it LOOKS HORRIBLE. I know I am going to get a headache from this in the next few days. And forget about developing anything with smooth animation (in a window. Full screen contexts still appear to work.) I wish I could downgrade to 10.2.2.
I'd run over to the Apple Store to see if it's just my machine or what, but being located inside the mall I'm hesitant to go anywhere near it until after New Year's.
late night coding session.