I don't know how many folks have attempted this but mSATA works great on an iBook G4! My iBook G4's HD died last week and since then I looked around for a replacement. Most spinning ATA drives are expensive new – probably because they aren't being made anymore. I thought about doing an mSATA upgrade but wasn't sure if it would even work on the iBook so I kept it cheap: Samsung 32GB mSATA III = $12 mSATA to 2.5" IDE Adapter + Enclosure = $12 To sum it up – the installation took over an hour and I really hope I don't have to do this, again. The last time I opened up an iBook was several years ago and I've been trying to prolong a repeat as long as possible so hopefully this will keep me good for several years. I installed 10.4 Tiger right after, installation was a breeze and really fast! I know that these old IDE drives are the bottleneck for the PPC computers as I have an iBook G3 also with an SSD that sometimes seemed to outdo both of my G4s when opening apps/files. The iBook is really fast, it boots up in seconds. I ran an Xbench test and it scored ~183 on the disk reading/writing benchmarks. Pretty sweet! You can see some screenshots below of the system profiler and Xbench results.