Skipping refresh cycle

Support
1

Hi Chris,

I am having trouble in one of the setups where I am getting continuous warning message of:
213:04:30: WARNING: Skipped 1 display refresh cycles
​

​The problem is that the drifting sequence of images don’t look smooth as they are in other computers. The problem must be computer specific but I can’t quite debug the source of it. Do you have any thoughts?

Thanks,

–
Sujay

2

Hi Sujay,

It sounds like the graphics hardware of this particular machine is struggling. What kind of Mac is it (year and model)?

If the hardware is identical to other machines that don’t exhibit this problem, then I’d suspect that either

  1. some other process on the machine is taxing the GPU, or
  2. the graphics drivers have gotten themselves in to a bad state.

If it’s (2), then rebooting the machine should resolve the issue.

Chris

3

Hi Chris,

It’s iMAC (24-inch early 2009) with OS X 10.11.6. The graphics card is ATI
Raedon HD 4850 512 MB. The hardware is not identical to other machines.
This machine is older.

Rebooting didn’t solve it - drift is still choppy and warning messages are
there in mworks console.

4

It’s iMAC (24-inch early 2009) with OS X 10.11.6. The graphics card is ATI Raedon HD 4850 512 MB.

For an iMac, nine years old is positively ancient. I’m not at all surprised that it can’t drive the display at a consistent 60Hz (or whatever its refresh rate is). Try something newer (or, at least, something with a newer or more powerful GPU).

Chris