Advanced Micro Devices Inc (AMD)

[CombJelly]

"The company shipped 13,002 servers with Intel's Xeon processor in the first nine months of 2004, of which 58 percent used Linux. For Opteron servers, Sun shipped 10,566, of which 73 percent used Linux."

And then there is this article...

With the Tuesday announcements, Sun became the second major server vendor to release systems based on Advanced Micro Devices' Opteron processor with the introduction of the Sun Fire V20z. It will be available in one-processor and two-processor configurations in April, says Neil Knox, executive vice president for volume systems at Sun.

http://www.pcworld.com/news/article/0,aid,114683,00.asp

So assuming they were available at the first of April, that means the Xeon servers shipped for 3 quarters and the Opteron for 2 to generate the above numbers...