When do you mean? In 2001?
It occurred to Yahoo, whose site had been run that way since almost the beginning, on FreeBSD. It occurred to Google, whose site was run that way since the beginning. It occurred to anyone who was watching the Top500 list, which was already crawling with Beowulfs — admittedly, not at the top of the list yet. It should have occurred to Intel, who were presumably the ones selling those servers to Yahoo and Penguin Computing and VA Research (who had IPOed in 1999 under the symbol LNUX). It had occurred to Intergraph, who had switched from their own high-performance graphics chips to Intel's by 1998. It had occurred to Jim Clark, who had jumped off the sinking MIPS ship at SGI. In 1994. It occurred to the rest of SGI by 1998, when they launched the SGI Visual Workstation, then announced they were going to give up on MIPS and board the Itanic.
I mean, yes, it hadn't occurred to most people yet. Because most people are stupid, and most of the ones who weren't stupid weren't paying attention. But it hadn't occurred to most people at Intel? You'd think they'd have a pretty good handle on how much ass they were already kicking.
> the joke is that cheap x86 processors did outperform Itanium (and every other architectures, eventually).
Even on my Intel laptop, more of the computrons come from the Intel integrated GPU. In machines with ATI (cough) and NVIDIA cards, it's no contest; the GPU is an order of magnitude beefier.