Intel uses what it dubs the “tick-tock” model of product design. The “tick” refers to rolling out a new manufacturing process--in this case, 22nm. The “tock” occurs when Intel ships a new microarchitecture using an existing manufacturing process. The current-generation Core i5/i7 Sandy Bridge CPUs represented a “tock.”
So the new Ivy Bridge processor is just a “tick,” right? The same thing on a new manufacturing process? That’s mostly true: The x86 CPU part of Ivy Bridge contains only minor tweaks to the current Sandy Bridge architecture. However, the GPU inside Ivy Bridge is a substantial redesign.
Basic Speeds and Feeds
On the surface, Ivy Bridge seems startlingly similar to Sandy Bridge. Comparing the two high-end models of the desktop CPU product line reveals almost no surface differences.
|FEATURE||Ivy Bridge (Core i7-3770K)||Sandy Bridge (Core i7-2700K)|
|Base clock frequency||3.5GHz||3.5GHz|
|Max. Turbo frequency||3.90GHz||3.90GHz|
|Shared L3 cache size||8MB||8MB|
|Graphics base frequency||650MHz||850MHz|
|Graphics max. dynamic clock||1150MHz||1350MHz|
|Max. supported memory clock||1600MHz||1333MHz|
|Thermal design power (TDP)||77W||95W|
Two key differences are immediately noticeable, and suggest what Ivy Bridge is really about. At the reference clock frequencies, Ivy Bridge is rated at 77W, versus 95W for Sandy Bridge. And the die size, at 160mm2, is 25 percent smaller. Ivy Bridge is both more power efficient and cheaper to produce--in terms of numbers of die per wafer--than Sandy Bridge. The Core i7-3770K is the high end of the Ivy Bridge lineup at launch, while the 3.4GHz Core i7-2600K was the high end at the initial launch of Sandy Bridge. It’s likely, then, that we’ll see higher-clocked Ivy Bridge CPUs in the future.
Another interesting difference is the clock-frequency disparity between the two graphics cores. Ivy Bridge’s GPU runs 200MHz slower than the Sandy Bridge GPU. However, the Ivy Bridge HD 4000 GPU offers additional performance since it has more execution units (16 versus 12) and texture units (two in Ivy Bridge versus a single texture unit in Sandy Bridge). For more information about the architectural changes in Ivy Bridge graphics, check out our companion story.
Next Page: Ivy Bridge Enhancements