At their peak, the attacks were flooding the sites with more than a billion bits of data per second, according to Paul Laudanski, the founder of CastleCops, one of the victims.

FORBES: Magazine Article

The latest attacks on Spamhaus saw speeds hundreds of times that, at 300 billion bits per second, or 300 Gbps.

FORBES: 'Biggest Cyber Attack In History' Could Have Been Carried Out With Just A Laptop

To put some numbers to that, average-sized DDoS attacks observed by cyber security researchers at Kaspersky Labs in 2011 saw data speeds of 70 megabits per second.

FORBES: 'Biggest Cyber Attack In History' Could Have Been Carried Out With Just A Laptop