ยง Networks are now faster than disks

I learnt of this counter-intutive fact first from this usenix article no SQL. On checking up, it seems to actually be true. Jeff Dean's keynote at LADIS 2009 report these numbers:
  • Round trip within same datacenter: 500,000 ns
  • Disk seek: 10,000,000 ns [regular disk]
On the other hand, a commentor on this discussion at serverfault mentioned that SSDs might be much faster, and the numbers bear out:
  • Read 4K randomly from SSD: 150,000 ns
  • Round trip within same datacenter: 500,000 ns
  • Disk seek: 10,000,000 ns [regular disk]