Duron 600 To 950: June 2000 To June 2001
There was a "slimmed down" Athlon for the Socket 462, with a quarter of the L2 cache (64 kB) - also known under its codename of Spitfire. This meant that the L1 cache - at 128 kB - was twice the size of its L2 cache. The transistor count was 25 million and it was manufactured using the 0.18 micron process. The bus speed was 100 MHz from the outset.
It made life difficult for the Intel Celeron 700: AMD Duron 650 with Spitfire core.
Duron 900 To 1300: May 2001 To January 2002
The enhanced version of the long-running Intel Celeron (II) competitor was based on the Morgan core and included new features such as SSE extensions and 3DNow+. The transistor count rose to 25.18 million and fabrication was based on the 0.18 micron process. Bus speed remained at 100 MHz.