Recently, I turned my two external drives into a Striped RAID Set. This means that I keep the cumulative size of them, as well as increasing the bandwidth throughput of the devices. I regularly do backups, so the horror stories of one drive dying doesn't bother me too much. I did notice however, that transferring files was much faster.
One other issue I was having was that I kept my music on external hard drives. This meant that if I travelled with my MacBook Pro, I would be left with the musical offerings of my iPhone and Spotify—both of which can be extremely lacking. My current SSD wasn't large enough to store my music library on, and therefore I couldn't carry it with me.
This got me thinking: What would two SSDs be like in RAID? Would this mean I'd be able to carry my music with me as well as have an altogether faster machine?
The first issue was that I needed a second SSD. I had an 80 GB Intel X-25M G1, and so focused on a second Intel SSD. For this, I settled on an 80 GB Intel X-25M G2 which is very similar to the prior generation.
The second problem was that I'd need to put this SSD in my MacBook Pro. Luckily, there have been several people who have done this before, and a friend suggested the iFixit.com Optical Bay SATA Hard Drive Enclosure.
I ordered both and fitted them myself. Setting up the RAID was easy using Disk Utility from a bootable pen drive. After using Time Machine to restore my entire previous system onto the RAID, it booted fine.
A thing to note is that Mac OS X can boot from RAID (I wasn't worried, honest).
So how was the performance?
The boot time seems very similar to previously. This could be due to the need to load the RAID information first, or could even be due to the fact I've now got VMWare Fusion installed. VMWare Fusion loves loading at startup: if you care to look at your Console after booting, you'll find many lovely notes from it.
Read and write performance doesn't seem to have changed much, while copying large files does seem a little faster. I decided that a totally scientific and infallible experiment should be done using XBench. The results are shown below, as you can see the overall improvements are minor.
However, I do now have 160 GB worth of storage in my MacBook Pro which means I can carry my music around with me.
Overall, while this may not make sense logically (or financially), it makes me really happy.