Mac OS X & FAH

Power Management on OS X - Something You Might Want to Set on Your Mac
OS X (PowerPC or Intel), by default, notices when the Mac is sitting or not doing much work and throttles the Processor(s) of the Mac back, so they slow down and use less power. The FAH client(s) for the Mac are set up so that they use only the extra CPU power available and when they run, OS X doesn't notice them as a reason for keeping the Processor(s) throttled up. Consequently, the Processor(s) get throttled back when the Mac sits or the user isn't doing heavy work and the FAH client runs extremely slowly. This has a major impact on the amount of work the FAH client does in a time period.

To remedy this situation, the user needs to change the Processor Performance setting on their machine. The following description applies to OS X version 10.4 Tiger.
 * Open System Preferences.
 * Click Energy Saver.
 * Click Options.
 * Click the Lock to authorize changes to the settings.
 * Click the Processor Performance and change it to "Highest".
 * Close the System Preferences.

The affect of this change on a user's FAH performance can be dramatic. How big an effect, depends on whether the User's Mac is sitting alot or not (that's when OS X normally throttles the Processors back). One user benchmarking the difference in performance, on a PowerMac G5 Quad with a single Terminal client, saw a 450% increase in FAH speed after making this change. Individual results may vary, but keeping the Processors throttled up (particularly when the user is away from the system) can only have a positive effect on FAH speed.

There are two additional consequences of this change to the Processor Performance setting. The first is that the Mac will use slightly more power than normal (since the Processors aren't getting throttled back when the Mac idles). The second is that the Processor will get hot as it works more - this won't hurt the CPU, Mac's are designed to have the CPU work hard, but it can make some laptops get warm (might not want it to sit on your lap while it runs) and drain their battery quickly. A good rule here is if you're going to have your laptop be on battery power, to temporarily disable the FAH client until you get the laptop plugged back in.