The MacBook Pro is unquestionably faster than the PowerBook G4 it replaces, but exactly how much depends on how you use it. Apple sells the MacBook Pro as "up to four times the horsepower of the PowerBook G4" but that's purely based on the SPECint and SPECfp benchmarks from Standard Performance Evaluation Corporation (SPEC). Apple's benchmarks were compiled using the IBM compiler and a beta version of the Intel compiler for Mac OS.
But SPEC benchmarks don't tell the whole story. I tested one aspect of the MacBook Pro's speed that affects me daily and is a better barometer of real world performance: application launch times. I benchmarked the MacBook Pro (2.0GHz) against a PowerBook G4 (1.5GHz) while launching 14 (native and Rosetta) applications and here are the results...
The first three benchmarks are Mac OS 10.4.5 boot times from being completely shut down. The rest are application launch times (in seconds) for both a PowerBook G4 (1.5GHz, 2GB RAM, 120GB HDD) and a MacBook Pro (2.0GHz, 2GB RAM, 120GB HDD). Overall the MacBook Pro boots twice as fast as the PowerBook G4 and applications launch about a third faster - and it sure feels like it.
| ||PBG4 ||MBP|
|Cold Boot to Apple Logo ||19:00 ||06:00|
|Cold Boot to Blue Desktop ||45:00 ||22:00|
|Cold Boot to Login Screen ||50:00 ||25:00|
|iPhoto 6.0.2 ||02:19 ||01:31|
|iWeb 1.0.1 ||02:13 ||01:50|
|iMovie HD 6.0.1 ||02:90 ||02:00|
|iDVD 6.0.1 ||05:15 ||04:81|
|GarageBand 3.0.1 ||09:00 ||06:78|
|Pages 2.0 ||09:62 ||05:94|
|Keynote 3.0.0 ||16:81 ||02:44|
|Safari 2.0.3 ||04:22 ||01:30|
|Mail 2.0.8 ||06:78 ||02:50|
|Address Book 4.0.3 ||05:00 ||02:40|
|iTunes 6.0.4 ||02:06 ||01:12|
|iCal 2.0.3 ||04:15 ||02:09|
|Photoshop CS2 (9.0x191) ||28:34 ||46:10|
|ImageReady CS2 (9.0x191) ||10:69 ||12:75|
Launch times were measured with a stopwatch in a new Mac OS X user account from the time the application was clicked in the dock to the time the application was ready for user interaction. Three launches were recorded and the high and low times were thrown out.