The point is that the industry effort to move to 64 bit, which consumed significant effort, and introduced (at the time) noticeable overhead in increased memory

The point is that the industry effort to move to 64 bit, which consumed significant effort, and introduced (at the time) noticeable overhead in increased memory consumption and reduced cache efficiency was unnecessary. There were solutions to all the problems encountered in 32 bit back in 2004 that could have been easily solved without doubling word size and creating the 32 / 64 split that means, at the least, all the Linux distros are shipping two versions of everything, for example. And the same thing is happening again, now. > we make 64-bit processing cheap for everyone. The business class that really has a practical use for >4GB per application already buys the extremely overpriced Xeon chips. Back in the day, those would have been Itanium, which were also 64 bit. There was a market for that technology in place before AMD64, and nothing about consumerizing 64 bit indicates it got cheaper - silicon is silicon, and the business world is big enough to easily support maintaining a technology end users don't need.