Instruments: Sampling in microseconds?

Using the Time Profiler or Counters instruments, you can select microseconds (it defaults to 500). However, when I look at my samples list, they are in 1ms intervals. Is there some trick to reducing the sample rate below 1ms?

Replies

If you're setting the sample rate before you start recording, this sounds like a bug. Please submit a report via https://bugreport.apple.com and include what device you're profiling, and the versions of Instruments, OS X, and iOS you're using. A trace document and details about how you're starting Instruments (via the Profile command in Xcode, or launching it directly) would also be useful.

I tried again this morning with a fresh instrument run to make sure I set it beforehand. It actually switches to milliseconds when I start recording and my samples list has 500ms intervals. The UI dropdown where I've selected microseconds actually switches back to milliseconds (as if the app is rejecting the microseconds selection).


I will file a bug report with as much info as I can.

I’m not able to find this sample interval setting with Xcode 10’s version of Instruments. Any one have a suggestion for me?

It no longer lets you select an exact sampling frequency. In the Recording Options (available from the File menu, or press-and-hold on the Record button), you can select High Frequency Sampling.