Athlon 64 X2 - Manufacturing Costs

Manufacturing Costs

Having two cores, the Athlon 64 X2 has an increased number of transistors. The 1 MB L2 cache 90 nm Athlon 64 X2 processor is 219 mm² in size with 243 million transistors whereas its 1 MB L2 cache 90 nm Athlon 64 counterpart is 103.1 mm² and has 164 million transistors. The 65 nm Athlon 64 X2 with only 512 KB L2 per Core reduced this to 118 mm² with 221 million transistors compared to the 65 nm Athlon 64 with 77.2 mm² and 122 million transistors. As a result, a larger area of silicon must be defect free. These size requirements necessitate a more complex fabrication process, which further adds to the production of fewer functional processors per single silicon wafer. This lower yield makes the X2 more expensive to produce than the single-core processor.

In the middle of June 2006 AMD stated that they would no longer make any non-FX Athlon 64 or Athlon 64 X2 models with 1 MB L2 caches. This led to only a small production number of the Socket-AM2 Athlon 64 X2 with 1 MB L2 cache per core, known as 4000+, 4400+, 4800+, and 5200+. The Athlon 64 X2 with 512 KB per core, known as 3800+, 4200+, 4600+, and 5000+, were produced in far greater numbers. The introduction of the F3 stepping then saw several models with 1 MB L2 cache per core as production refinements resulted in an increased yield.