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MisterMe

macrumors G4
Jul 17, 2002
10,709
69
USA
OnyX is just a GUI on top of standard UNIX tasks. Therefore, the utility does nothing that is not done on virtually every other UNIX-based OS installation on Earth.

Having said that, caches are designed to speed-up certain operations. If you wipe cache files, then it is possible to experience minor slow-downs until the cache is rebuilt.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,545
943
No, OnyX isn't slowing down your computer. However, many of the functions aren't necessary unless you're performing specific troubleshooting.

If you're having performance issues, this may help:
You don't need "cleaner" or "maintenance" apps to keep your Mac running well, and some of these apps can do more harm than good. Most only remove files/folders or unused languages or architectures, which does nothing more than free up some drive space, with the risk of deleting something important in the process.
These apps will not make your Mac run faster or more efficiently, since having stuff stored on a drive does not impact performance, unless you're running out of drive space. In fact, deleting some caches can hurt performance, rather than help it, since more system resources are used and performance suffers while each cache is being rebuilt.
Many of these tasks should only be done selectively to troubleshoot specific problems, not en masse as routine maintenance. OS X does a good job of taking care of itself, without the need for 3rd party software. Among other things, it has its own maintenance scripts that run silently in the background on a daily, weekly and monthly basis, without user intervention.
 
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