The M500 series are among the highest power consuming drives -- their only bad point, really. Other modern drives (eg. Samsung) use less power.

The total assembly is about half the size of a normal notebook drive. You can just tape it up and cable tie it to the drive tray. No problem with two fitting in.

I probably pre-date you on the curling stone style drives. And my first hard drive at home was a whopping 5MB !!!