Diagnosing a slow running Mac – Part 3: Storage

This short series will discuss some of the common problems that can slow your Mac down dramatically. In this installment we’ll look at hard drive performance.

If you’ve eliminated RAM and processor performance, then the next thing to look at is the hard drive. For just about every action you ask the computer to do, it has to read or write data to the hard drive. This is, in computer terms, extremely slow. So if you are using Photoshop, Final Cut, InDesign or other programs that extensively use the disk, you will often find that you have RAM to spare, the CPU is barely ticking over, but the machine feels unresponsive because it’s thrashing the hard drive. So what can you do to improve this?

1. Make sure that you have at least 20 GB of free disk space, more if you can. Hard drives slow down as they get more full, as continuous sections of free space get harder to find, and data gets written to the inner, slower sections of disk. Don’t de-fragment – get a bigger disk.
2. Check the disk for errors using Disk Utility or another tool. Repair if necessary.
3. Check the system.log for disk I/O. If you see any backup your entire drive and replace it at the first opportunity.
4. Get a faster drive. You can achieve this in any number of ways, spending from £50 to many thousands.

The easiest and cheapest option is to just replace the internal drive with a faster speed drive. So if you have a 5400rpm drive, get a 7200 rpm, 10,000 rpm or 15000 rpm model. The next option is to get a faster drive by setting up a RAID 0 “Striped” array. Personally I think you’re nuts if you do this without a rock solid backup system. My preferred option is to replace the startup disk with a Solid State Disk (SSD).

SSDs can be massively faster if you choose your model carefully. You have to be particularly careful if you use a Mac, because OS X doesn’t support the TRIM command that helps keep many drives fast and healthy. Apple do supply Configure To Order (CTO) MacBooks and iMacs with SSDs, but they don’t have a history of fitting the highest performing drives available. My advice is to choose your own SSD and then get it fitted. As of now, the rule seems to be buy a drive with a “Sandforce” controller to get the best performance on a Mac that maintains that performance. The greatest perceived improvement will be seen by MacBook owners, as laptops drives are even slower than the bigger desktop models.

Because SSD drives are comparatively expensive when measured in cost per GB storage against traditional “spinning disk” hard drives, often people dismiss them as an option as they don’t offer enough storage. However, I’m currently fitting an internal SSD into my MacBook Pro, giving me a 64GB SSD boot drive and a 250GB SATA drive that replaces the Superdrive. This means my MacBook has 2 internal drives, one screamingly fast that runs OS X, applications and scratch space, the other tolerably quick that holds the majority of my data.

Looking for a professional SSD upgrade service for your MacBook Pro, Mac Pro or iMac? Want to fit an extra internal hard drive to your MacBook Pro? Please get in touch…