OK, I got this from the following link: http://www.macosxhints.com/article.php?story=20031127211855401&query=sysctl Here is one person's testing results: Authored by: ahbe on Thu, Dec 4 '03 at 12:40PM Ok listen up, this should answer many of your questions. Here's my setup: 867Mhz 12" Powerbook OS X Panther 10.3.1 Xbench 1.1.3 I created a new account just for this test. This is mostly because my primary account has a bunch of stuff running in the background, and I wanted to make this as subjective as possible. So, after a fresh restart I logged into my newly created account and did a sysctl hw.cpufrequency and got back an answer of 533Mhz like everyone else. I ran Xbench on CPU test only and after several dozen tries, got an average of about 98.3 (It varies slightly). I than shutdown my powerbook, and reset the PMU. When I started it back up and logged into my special account and did a sysctl hw.cpufrequency test again, this time it said my CPU was running at 866MHz. Much better. I then ran Xbench again, and guess what. I got the EXACT same scores. Somewhere around 98.3. So, what does this tell me? sysctl doesn't tell you anything. Ignore it. In fact, just restarting my computer, not reseting the PMU, will give me different answers when I do a sysctl hw.cpufrequency. Sometimes I get 533MHz, sometimes I get 866MHz. So, at least on my 12" Powerbook, it doesn't matter. Any perceived speed increases are just in your head. Hope this helps. -- Ahbe So, it appears that some Powerbooks (1 Ghz Powerbooks and 12" Aluminium books in particular) return an incorrect value in Terminal and other similar UNIX utilities. jg