I'm looking to get a Macbook Pro. The base model comes with a 2.2Ghz processor and I'm evaluating whether the 2.3Ghz upgrade is worthwhile. Clock speeds are confusing to me I remember having a 3Ghz Pentium IV. If I get the upgrade is it only a 4.5% improvement or is there something that I'm missing?
Modern processors are simply more efficient - pentium IVs had notoriously bad real performance for their clock speed - A contemporary pentium M (and allegedly even a PIII) could run circles around it, despite a lower clockspeed. In addition, modern processors have more cores ( a 2.2 ghz C2D is TWO 2.2 ghz cores).
If its an even more modern architecture, such as the latest AMD chips or the intel sandy bridge processors, they also have additional features on chip - such as memory controllers and integrated GPUs - which, while not increasing the clockspeed, take up transistors, but reduce communications latency - which means better real performance
Processor speed dosen't mean as much as it used to - you arn't using more than 10-20% of your processor most of the time - so unless there's other differences in specifications, the small clock speed difference won't make a big difference.
Its more than ghz, the 2.3 has more on board cache, 8 mb vs 6 for the 2.2 about a 10% performance enhancement overall.
GHZ is lower than the old days, because now you have 4 processors total, 2 cores with each core having 2 threads. Each core is 2.3 , so a total of 4.6 theoretically.