Asgard hyperdrive

Asgard hyperdrives are designed to reach distant galaxies in minutes. They gave Earth their hyperdrive systems for the new Daedalus class battlecruisers as thanks for helping defeat the Replicators. However, the Earth ship power sources are much weaker, and hyperdrives deployed appear to be less advanced than typical Asgard ships, so it takes them three weeks to get to the Pegasus Galaxy, though this speed is still far beyond anything other advanced races such as the Goa'uld or Wraith can accomplish. A ZPM would allow the Earth ships to reach Pegasus in four days. The Odyssey was recently fitted with the newer Hyperdrive, and it is likely the technology will propagate to other Earth ships.