Xserve Xeon: Upgrade your own CPUs, but AYOR

Apple's laudable and full embrace of the x86 system architecture standard creates an interesting possibility that prior Macs (other than Mac Pro) haven't offered: CPU upgrades. Xserve's Intel Woodcrest CPUs are seated in simple, x86-standard ZIF (zero insertion force) sockets. You just remove four ordinary screws holding down the very pricey full copper heat sink, lift one lever, and out pops the CPU. The only inconvenience is that you'll have to acquire a tube of thermal goop.

When competing first-tier vendors are found to be locking standardized components down, please take them to task and get an on-the-record explanation regarding their efforts to make off-the-shelf parts non-replaceable. I do ask, and I've heard: "Our advanced heat sink design requires riveting it to the bottom of the chassis;" "We run our [marked-up] CPUs through a more rigorous validation process than Intel does;" "We find that few of our commercial customers wish to service or upgrade their own systems;" or, as you've heard from me before, "The minimum field replaceable unit is the system." Of these, only the last holds any water. If you've ever had what passes for a PC vendor's on-site service call, you know why (I've had no experience with Apple's on-site service).

Intel's next CPU, Clovertown, is on deck for early 2007. This four-core uses the same pinout as dual-core Woodcrest, and the die is exactly the same size. Intel built Woodcrest to so it could swap out with Clovertown. That drop-in replacement design (which AMD pioneered; Intel will not keep Server CPUs socket-compatible for three years) is primarily a build-time cost saving for OEMs. Woodcrest and Clovertown machines at a range of clock speeds can be built using the one motherboard and a single assembly line. But that also means that you can yank a Woodcrest and drop in a Clovertown, or a faster Woodcrest, as long as the system's firmware doesn't preclude it.

I wouldn't try it with any system in production that's under warranty.

So, why should I celebrate a capability that I advise readers not to exercise? It's simple, and I say it time and time again: How vendors build their systems speaks volumes about their attitudes toward their customers. It's cheaper to nail down components than to make them easily replaceable, and nailing them down improves the chances that buyers will buy new servers when they need faster ones. Apple could have gone that way with Xserve. Instead, Apple has embraced the Intel x86 standard system architecture in a way that would pass muster with purists.

Although Apple took the off-the-shelf route, it didn't get there by buying a tract chassis or punting logic and layout to Intel's reference design.