How Fast Is Your Disk?

Let me introduce you the Corner CP2064, a 2.5 inch harddisk produced in July 1991. With a capacity of only 64 million bytes it is the smallest hard disk I ever owned. Today it could store approximately 20 pictures from my phone.

More importantly it is also the slowest disk I ever developed software for. The theoretical bandwidth is 1.5 MB/s - in practice less than half of that was achievable. Random accesses were limited to 30 per second due to long seek times and slow rotational speed. The maximum power consumption was 2.8W.

Today I have a 990 Pro SSD with 2 TB in my laptop. It can read 7 GB/s sequentially and can sustain 1.3 million random reads per second. It may consume up to 8.5W though.

Performance wise this corresponds to four orders of magnitude improvement over the last 30 years. Or roughly doubling every 2 years.