Ask Different is a question and answer site for power users of Apple hardware and software. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Simply put, I'm looking for a utility akin to Windows NT's Performance Monitor (perfmon.exe). The ability to specify which metrics I want to track (ex. reads/sec, writes/sec) for a given object (ex. Macintosh HD), and ideally, for all or specific processes.

The use case is we have a developer at the office whose MacBook has abominable disk performance. I/O is bad enough to the point where it may be blocking. It's evident from Activity Monitor that there's an average of 80-110 IOps, but at this point it'd be advantageous to pin down what the offending processes might be (it's certainly not mds or mdworker). Although using DTrace scripts such as IOSnoop would probably work, a graphical tool (including non-free) that would provide easier visibility into these (and other) metrics would certainly be preferred.

share|improve this question
Instruments is the equivalent tool - free with Xcode - this question has two command line tools to attack/illuminate file IO as well. – bmike Sep 30 '11 at 3:14

XCode 4's Instruments is certainly a viable choice that looks as if it'll get the job done. -- you can profile specific processes/agents/daemons and change the active target during the session. However, developer tools are not a common install on most computers (and it's a large download).

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.