Intel's strategy is a little different to AMD's. AMD had the intention of changing the world 64 bit with the release of the Athlon 64, but Intel have dragged their heels. X86-64 (which Intel call EM64t, I will refer to it by this from now on) is only just becoming available on the desktop Pentium 4's, even though it has been in the server processor, Xeon, for a few months now. Intel have been much more interested in 32 bit performance, bumping their clockspeeds as high as they could go. They finally hit a wall, 3.8GHz, and as a result are now forced to find new ways to increase performance. One of these ways is to increase the cache, and another is to implement 64 bit into all their new processors.