The CPU Is Not the Bottleneck

After spending the last few years keeping an eye on the CPU and memory usage of a fairly average MacBook Pro, eWEEK Labs Senior Analyst P. J. Connolly is convinced that processor speed is no longer the obstacle to system performance for the vast majority of use profiles; instead, memory is the stumbling block in today's Web 2.0, Flash-enabled, social networking-obsessed world. Although the new MacBook Airs have inferior processors to those found in a 3-year-old MacBook Pro, the limited memory configuration, which tops out at 4GB, is where users can expect to run into problems.

I wonder when people are going to wake up to the reality that the CPU of a mobile computer is no longer the factor that determines how useful the device is. Ever since the new MacBook Air models were announced on Oct. 20, I have been seeing articles-with perhaps the most widely distributed one coming from Ars Technica's Chris Foreman-discussing how awful it is that Apple chose the Intel Core 2 Duo as the CPU for the new Airs.

To steal a line from Dear Abby, people need to wake up and smell the coffee. As I've discussed before, the choke points for the casual user are the system memory and the content that one's viewing online. I'll concede that my experience may be anecdotal, but only because I don't record every last tick of the machine; however, I've been keeping an eye on the CPU and memory usage on my own MacBook Pro for the last several months, and I have a couple years' worth of observations that form the basis for my opinion.

A couple of years ago, there was no question in my mind that the CPU was still the bottleneck. At that time, I was using two machines for bread-and-butter work: an early-model MacBook Pro with a Core Duo for business and a PowerBook G4 for fun. As I've mentioned many times, I'm addicted to opening browser windows, and on both of those machines, I could easily redline the CPU many times throughout a typical day.

I switched to a MacBook Pro with a 2.2GHz Core 2 Duo almost a year ago, and since then, I've noticed a big difference; I rarely redline the CPU now, but I can max out the system memory without any effort. Even after doubling the RAM in that machine from 2GB to 4GB, the system runs out of free memory well short of my record of 220-plus browser windows. That personal best dates from early 2009, well before Facebook and Twitter had taken over the Internet. Where does it all go? The answer is Safari, with a little help from Flash-I can max out the RAM with only 50 or 60 open browser windows, and Safari will eat up half the memory if I let it.

The Core 2 Duos that are in the new Airs are in the mid-1GHz range, and the 13-inch models can be upgraded to a 2.13GHz processor. That's not screaming fast, but it's very power-efficient. Although they're not quite as fast as the CPUs in my 3-year-old MacBook Pro, that's not what's keeping me from running out to buy a new MacBook Air. No, it's the limited memory configuration of the new Airs that's turning me off; they come in 2GB and 4GB configurations, and if I'm maxing out at 4GB today, can you imagine how unhappy I'll be in a year or two?

I suspect that if you talk to the average PC user, you'll find that the main complaint is that Web pages take too long to load. I see two reasons for this: First, the sites that the average user is likely to visit rely on Flash to display content; second, those sites are also pulling a fair amount of content from third-party sites such as Facebook and Twitter.