The world's first hard drive was a massive unit released by IBM in 1956. Called the IBM 350 Disk Storage, it came with the IBM 350 RAMAC system. The 350 measured 60 inches (L) by 68 inches (H) by 29 inches (D) and had 50 magnetic disks containing 50,000 sectors. It had a small air compressor, electronic and pneumatic controls, and 5MB of storage capacity. Compare that to today's top deal for a Western Digital RE 4TB 3.5-inch Enterprise Internal Hard Drive for $310 with free shipping (normally $335 - use coupon code: [EMCPGHE27]). It's devoid of an air compressor, but it does have 64MB of cache, a SATA 6Gbps interface, a 7200 RPM spindle speed, and multi-axis shock sensor, to name some of the highlights.