Intel Core i5-661 Performance Preview

For a little over a year now, Intel’s been slowly phasing out Core 2, one of their most successful CPU architectures of all time. The process started in November 2008 with the introduction of Intel’s first Nehalem processors, the Core i7-920, 940, and 965.

Thanks to their new architecture (which shared many similarities with AMD’s latest processors), these CPUs blew the doors off the fastest Core 2 CPUs, and did so while remaining energy efficient.

Upgrading to one of these CPUs wasn’t cheap though. A motherboard based on Intel’s X58 chipset is required, and as anyone who’s ever shopped for an X-series chipset can tell you, these extreme motherboards can get pretty pricey. Even today a stripped-down X58 motherboard usually goes for $170-$200, while midrange boards sell for $250+. A fully loaded X58 motherboard is priced over $300.

Therefore in order to appeal to the more price conscious crowd, Intel introduced their first mainstream CPUs based on the Nehalem architecture last September. These CPUs are based on Intel’s “Lynnfield” core and are designated as the Core i5-750, Core i7-860, and Core i7-870.

With their aggressive Turbo Mode settings and large cache, these CPUs were able to deliver the same blazing performance we saw from Bloomfield at the end of 2008, but with lower CPU and platform costs. Core 2 Quad instantly became overpriced and obsolete. We’ve been recommending Lynnfield processors for all but the most demanding hardware enthusiasts and gamers.

Now Intel’s got their sights set on dual-core computing. Today Intel’s rolling out their first dual-core CPUs based on the Nehalem architecture. These CPUs rely on Intel’s “Clarkdale” core.

That’s not the only first for Clarkdale though. Clarkdale is also Intel’s first processor to utilize their brand new 32-nm manufacturing process. Historically Intel has reserved new process introductions exclusively for their high-end CPUs where volumes are lower; this allows them to work out any kinks in the process without potentially running into supply issues.

However, Intel’s so confident with their 32-nm process they’re starting with the high-volume parts first; Intel’s 32-nm CPU for the high-end segment, the 6-core Core i7-980X “Gulftown”, isn’t expected to debut until Q2’2010.

Clarkdale’s 32-nm manufacturing process isn’t the CPU’s most dramatic new first though. That honor goes to its integrated 3D graphics core, which is built into the same package as the CPU.

Integrating graphics into the CPU is quite a coup for Intel. It wasn’t long ago that we expected AMD to finish first here…

The race to bring 3D graphics to the CPU

It all began on July 24th, 2006.

On that day, AMD announced their plans to acquire graphics maker ATI in a deal valued at $5.4 billion. The news shook up the CPU and graphics landscape, setting off a chain of events that has helped lead us to today’s Core i5 and Core i3 “Clarkdale” CPU introductions.

As AMD saw it, one of the keys to taking CPU share away from Intel was to offer more compelling platforms as a whole. Having the world’s fastest CPU was good, but to get to that next level, they felt they had to offer the complete package for PC manufacturers and vendors. This was particularly important on the mobile side, where Intel has enjoyed tremendous success with Centrino and other products. AMD’s K8 generation of CPUs never enjoyed much penetration in this space, and as we all know, the mobile segment is where most of the growth is in the overall PC market.

Key to executing on this strategy was AMD’s first CPU with integrated graphics. The first CPU+GPU core was initially codenamed “Fusion”. Back in 2006, AMD expected their first Fusion processor would debut sometime in 2008, which is when they originally planned to transition to 45-nm. Shrinking the manufacturing process down to 45-nm was critical for Fusion to occur, as the smaller process was needed to fuse graphics onto the CPU without the final product costing an arm and a leg for AMD to manufacture.

Of course by now we all know how things ultimately played out. AMD’s 45-nm transition didn’t occur until early 2009, and AMD changed course, deciding to wait until 32-nm before they integrate 3D graphics into the CPU. This won’t occur until AMD’s “Llano” core is introduced sometime in 2011 -- some 3 years later than AMD’s initial projections, and a year behind Intel.

In AMD’s defense, their original goal with Fusion was to integrate a more robust graphics core akin to the one used in their 780G IGP. Intel’s approach with Clarkdale is a little more conservative: its graphics core is largely based on their existing GMA 4500 IGP used in their G45 chipset. We’ll be going over the tweaks Intel has integrated into Clarkdale’s graphics core on the next page, as well as the changes to the CPU die itself as well.