Speed of Replication animation

Prokaryotes

The single molecule of DNA that is the E. coli genome contains 4.7 x 10⁶ nucleotide pairs. DNA replication begins at a single, fixed location in this molecule, the replication origin, proceeds at about 1000 nucleotides per second, and thus is done in no more than 40 minutes. And thanks to the precision of the process (which includes a "proof-reading" function), the job is done with only about one incorrect nucleotide for every 10⁹ nucleotides inserted. In other words, more often than not, the E. coli genome (4.7 x 10⁶) is copied without error!
 

Eukaryotes

 The average human chromosome contains 150 x 10⁶ nucleotide pairs which are copied at about 50 base pairs per second. The process would take a month (rather than the hour it actually does) but for the fact that there are many places on the eukaryotic chromosome where replication can begin. Replication begins at some replication origins earlier in S phase than at others, but the process is completed for all by the end of S phase. As replication nears completion, "bubbles" of newly replicated DNA meet and fuse, finally forming two new molecules.

after Kimball  http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/DNAReplication.html

Okazaki Fragment  =

A relatively short (100-1000 bp) fragment of DNA that is later joined by DNA ligase to allow for 3' → 5' overall chain growth during replication.