Intel's Silverthorne Unveiled: Detailing Baby Centrino

Final Words

With Itanium, Intel felt that it was being limited by the x86 ISA (Instruction Set Architecture) and set off to develop the perfect instruction set and CPU architecture for its target markets. That was a very different time; if you remember back to AMD's introduction of x86-64, one thing AMD made a point of saying was that ISA no longer mattered - the penalty for going x86 was so small in comparison to the total chip complexity that it was a far better move to maintain software compatibility than get slightly better efficiency but break x86 support. With Silverthorne Intel has come full circle and embraced the same ideal; the goal is to have x86 from top to bottom and the range now includes ultra mobile devices once reserved for ARM processors.

In every market segment Intel has entered with x86, it has managed to dominate based on two principles: manufacturing prowess and x86 compatibility.

The manufacturing advantages Intel has held over the years are evident. Intel's incredible investment in fab plants around the world requires that it keeps them running as close to full capacity as possible. The market for low cost, low power silicon like Silverthorne is huge and should give Intel the ability to continue to hold onto a manufacturing advantage in the future. Intel won the server market by being able to subsidize the cost of manufacturing server CPUs by making even more desktop chips that needed the same fabs. The market for ARM-based processors is even larger than Intel's desktop CPU demand, so Silverthorne has the ability to have dramatic effects on Intel's overall CPU business if demand grows as expected.

The x86 compatibility aspect of Silverthorne is huge, and once again we turn to the iPhone example. The iPhone is Apple's only non-x86 product in its lineup, a lineup that runs in some shape or form a version of OS X. Maintaining separate software stacks for the iPhone vs. the rest of the product line isn't ideal; it increases the overhead and cost of software development and debugging. The 32nm successor of Silverthorne will be the chip that Apple will be able to stick in its 4th generation iPhone, giving it a single x86 software stack across all products.

There's significant competition to Silverthorne, and I don't expect it to be very successful in its first incarnation. ARM-based devices are simply smaller and used in very different ways than where Silverthorne is going to find itself. At first Silverthorne is simply going to compete with Intel's own ultra low voltage processors used in UMPCs, but it will slowly enable a new class of devices.

Inevitably the comparison to VIA's recently announced Isaiah CPU will be made, but Silverthorne is really aimed at a different market. Isaiah is a higher performance out-of-order core, while Silverthorne is eventually designed to make its way into highly integrated CE devices. We expect VIA's latest creation to outperform Silverthorne, but we don't expect the two to actually compete in the same space.

Moorestown's higher level of integration will bring about smaller devices, but still nothing iPhone-class. In our opinion, it won't be until after 2010 that we will really see the Intel/ARM race heat up. If you're expecting Silverthorne to revolutionize the ultra mobile world the way Centrino did upon its launch, you will be disappointed. What we are seeing however is the beginnings of what could be revolutionary. Intel's vision is clear; it's just up to Moore's Law to make the technology small, cool and powerful enough.