AMD Athlon "Thunderbird" 1 GHz / 800 MHz

Expendable is a situation where raw processing power matters more than having a fast L2 cache, which is the only real advantage the Thunderbird brings to the table in addition to what the Athlon can already boast. For this reason you don't notice a huge performance increase between the 1GHz Athlon and the new 1GHz Athlon running on the Thunderbird core.