[mabhatter]

The performance is in the SYSTEM architecture. Even a mid sized POWER box can address Hundreds of gigs of RAM, Petabytes of direct attached disk and rooms full of tape stored data. You can make an x86 box do that, but it's not really supported at the "plug bits and go" level. You put POWER boxes in place and don't reboot them for years. (Unless you are smart and do your HA/DR tests like a good kid)

For example a Google plays around with racks of disposable X86 boards like candy. When their app becomes "fixed" rather than growing exponentially, they'll want to move to something like POWER because it's DESIGNED to work with dozens of CPUs sharing Petabytes of attached disk easily. Not the silly kludges like Blades, SANS or iSCSI or virtual machines people play with now to hide x86 OS vendor scaling limitations.

[zvrba]

What you're describing sounds more like a combination of better HW (bus, components) and SW (operating system). I agree, IBM delivers superb systems.

However: are there any inherent limitations in the x64 architecture which would make it impossible to achieve the same as with POWER, if you designed it from scratch for that kind of robustness?

[anentropic]

any sign of this transition happening at Google?