Apple's MacBook Pro with 128GB SSD: Performance and Battery Life Investigated

Better Application Performance? Not Exactly

If battery life didn't improve, surely it must be a sacrifice made in the name of better application performance right? Not exactly.

To understand why, we must first look at the synthetic performance of the drive:

In sequential access, small block reads and writes either don't improve at all or improve by an amount that's not huge (15% for uncached writes, but that's just an improvement in the performance of your disk subsystem - not the entire machine, expect real world performance improvements to be some fraction of that). Larger accesses are a bit more favorable, with reads and writes improving by 37% and 51% respectively.

Most single-application desktop usage models are actually very heavy on sequential disk access, and in these situations you won't see the biggest performance benefits from a SSD - even something as fast as the Memoright.

Looking at the random reads however tells another story:

While random writes offer a ~20% performance improvement, random reads range from 3x - 20x the speed of a mechanical disk. Now since most single-application usage patterns tend to be sequential in nature, we don't see these incredible performance gains in many of our scripted tests - however, in actual usage you can easily feel a bigger difference.

This is where the whole: once you go SSD, it hurts to go back statement from the introduction of this article comes from. Within a single application, performance may not improve a ton, but your day to day usage experience will be a lot smoother.

Let's take a look at some of those application tests:

The biggest performance increases here are in the iPhoto Import, Keynote Export and Word Compare Documents tests. Performance went down slightly in the iPhoto Export and PowerPoint tests, but the drops were so small that they can be considered insignificant.

The major take-home point here is that performance didn't go up all that much in most of these tests, with the biggest gain being just under 14% that's a marginal improvement given the nearly $4,000 price of admission.

But there is just one more thing...