Like many USB-only drives, on older laptops the My Passport may not be able to draw sufficient power to operate from the bus alone, and so an auxiliary cable may be necessary-it’ll cost an extra $10 from Western Digital. The drive gets a bit hot as the fanless aluminum case works to draw heat away from the drive mechanism, but the upside is that the drive ran quietly throughout our tests. But for all the abuse, the drive didn’t slow down a bit and showed little wear. I put it through our series of handling tests, which include tossing the drive around my cubicle and dropping it to the ground several times to see how it handles the punishment. WD My Passport External Is Recognized on Mac but becomes Inaccessible Another situation is that the WD my passport portable hard drive can show up on Mac OS when you plug it to your computer, but the problem is that you are unable to access any data. I am a college student and purchasing this was an absolute no brainer. It is fast, simple set up, and the ease of use which makes it perfect. The My Passport is a simple, light drive. My WD Passport for the Mac is the best external hard drive anyone can buy for the Mac computer. With a 500GB capacity, a three-year warranty, and a shock-resistant shell that can withstand your average wear and tear, the My Passport is one of the best portable drives we’ve seen for the Mac. Western Digital’s My Passport For Mac is a solid, compact, comparatively speedy little USB-only portable hard drive that also happens to be Time Machine–ready and designed for the Mac.