I’m thinking about taking out my MacBook Pro’s optical drive and replacing it with a 2 TB hard drive. I checked out some hard drives and I noticed that Seagate has two drives which are very similar and the only difference between them is that one has a 32 megabyte cache while the other one has a 128 megabyte cache. I’ve noticed that if I’m watching a movie in the backseat of a moving car and the car hits a bump in the road, the stock 5400 RPM hard drive would stop playback momentarily as the read/write head needs to find the spot where it left off. Would a 128 megabyte cache help avoid that problem? Or is a 32 megabyte cache sufficient? By the way, I discovered that the stock drive has an 8 MB cache.