When Apple made the switch from packing its computers with PowerPC chips to using faster Intel ones, it needed to find a way to let older, PowerPC-only software still work in OS X on Intel machines. Emulation was the answer that enabled most PowerPC programs to run fast enough to be useable. However, this emulation can also be troublesome when accidentally invoked, so…

Watch Out for Rosetta

I have an iMac PowerPC G5 in my office that I do most of my work on. My wife, Michelle, almost exclusively uses our newest computer, an Intel MacBook. For browsing the web, I use Safari in my office but have always used FireFox on the MacBook as I found it to be considerably faster than Safari. I chalked it up to the Intel build of Safari being less efficient than the PowerPC one.

Since we got the MacBook, Michelle has told me on a number of occasions that it was too slow. Every time I used it, I thought it was extremely fast, especially when compared to my older iMac. I could never figure out why she thought it was so darn slow when I thought it was quite speedy… until the other day.

I was using FireFox on the MacBook to look at a few web pages, including Yahoo. Everything was loading fine. Then Michelle wanted to check her e-mail, so I handed her the computer and watched her bring up Safari, followed by an extremely slow-loading Yahoo home page - much slower than I had just loaded it a few minutes prior. It was time to figure out why Safari was acting so sluggish.

After uninstalling the latest beta of Safari 4 and returning it to the more-stable Safari 3, I found that it was still equally as slow. I cleared the cache, cookies, and changed several more settings with no change in speed. Finally, it occurred to me to check to see if Safari had somehow been switched to running in Apple’s PowerPC emulation mode called Rosetta. Sure enough, it was.

Upon unchecking the box telling it to use Rosetta, I instantly found Safari to be just as fast as FireFox ever was. Michelle is much happier using that machine now as well. I have no idea why Safari was ever set to run in Rosetta, but I’m glad I finally figured it out.

The moral of the story is if you are using an Intel-based Apple computer and find a particular program to be running much slower than you think it should be, try the following steps:

1. Locate and highlight the application in Finder.
2. Right-click on it and select Get Info (or press command-I on the keyboard).
3. Look for an option that reads “Open using Rosetta”.
4. If it is checked, uncheck it.
5. Celebrate.