Intel goes 22nm with ‘Ivy Bridge’ 3rd-generation Core processors. Springtime has arrived, and that can only mean one thing: Ivy Bridge is here! Okay, so it also means fighting the temptation to turn on the air conditioning for even slightly elevated temperatures.
Both AMD and Intel know that great products create lofty expectations. When you follow up an Athlon with an Athlon 64, or a Core 2 with a Core i7, customers start looking for big progress from subsequent generations, too.
Well, we all know that Sandy Bridge was a home run on the desktop. Can all of the enthusiasts who posted to forums about waiting for Ivy Bridge really be faulted for hoping to see another round of impressive performance gains?
Ivy Bridge was never projected to be as impactful as its predecessor, though. The company’s “tick-tock” cadence defines alternating steps forward in processor architecture and manufacturing technology. When Intel pulls off a successful new design based on mature lithography, the improvements tend to be big, bold, and beautiful. Nehalem and Sandy Bridge, both “tocks,” left us satisfied and smiling. A process shrink typically introduces other benefits, such as smaller dies and power savings. Benchmark results, however, typically don’t change as drastically.
Westmere was Intel’s most recent “tick,” heralding the arrival of 32 nm transistors. The company used more diminutive geometry to create room for additional cores on its fastest desktop-oriented CPUs, giving us chips like the Core i7-990X.
Today’s Ivy Bridge launch represents the next “tick”—a 22 nm die shrink of the same fundamental architecture we already know as Sandy Bridge. Intel is calling it a “tick-plus,” though, because there actually are a few under-the-hood improvements.
Unfortunately for desktop enthusiasts, the most significant changes center on the design’s integrated graphics engine, which most of us simply don’t utilize.
Naturally, the story is different in the mobile space, where lower power consumption and “fast enough” 3D capabilities combine to enable big battery life numbers and surprisingly acceptable performance. But today’s Core i7-3770K review doesn’t cover a mobile processor. Rather, we’re looking at Intel’s fastest multiplier-unlocked model, positioned to succeed the existing Core i7-2700K and -2600K.
Meet Ivy Bridge
Intel built Sandy Bridge-based chips in three different configurations: one quad-core and two dual-core designs. The most complex implementation included 995 million transistors in a 216 mm² piece of silicon. In comparison, the biggest Ivy Bridge die incorporates 1.4 billion transistors on a 160 mm² die.
If you were to show your grandmother die shots of Sandy Bridge and Ivy Bridge, she should be able to point out where most of those 400 million new transistors were added. Clearly, the built-in graphics engine is more prominent.
Much of the expansion is attributable to an increase in execution units—the programmable shaders responsible for graphics processing—which Intel claims boosts 3D performance by as much as 2x. Sandy Bridge’s HD Graphics 3000 employed 12 EUs; Ivy Bridge’s HD Graphics 4000 pushes that number to 16. HD Graphics 4000 also uniquely supports DirectX 11, up to three display outputs, OpenCL and DirectCompute, and better Quick Sync performance, all of which we’ll test for you.
The rest of the layout should look fairly familiar. Given a mainstream focus, the die-driving Core i7-3770K is a quad-core, Hyper-Threaded part with 8 MB of shared L3 cache divided up into four 2 MB slices, same as the Core i7-2600K we reviewed more than a year ago. There are a handful of small tweaks to what the cores themselves can do. Intel says that those adjustments, plus tweaks in the cache and memory controller, help improve the number of instructions per clock cycle this architecture executes. We’ll be running per-clock comparisons between Ivy and Sandy Bridge to help quantify those claims as well.
|Header Cell – Column 0||Cores / Threads||Base Freq.||Max. Turbo||L3 Cache||HD Graphics||Graphics Base Freq.||Graphics Max. Freq.||TDP (W)||Price|
|Third-Gen Core i7 Family|
|3770K||4/8||3.5 GHz||3.9 GHz||8 MB||4000||650 MHz||1.15 GHz||77||$313|
|3770||4/8||3.4 GHz||3.9 GHz||8 MB||4000||650 MHz||1.15 GHz||77||$278|
|3770T||4/8||2.5 GHz||3.7 GHz||8 MB||4000||650 MHz||1.15 GHz||45||$278|
|3770S||4/8||3.1 GHz||3.9 GHz||8 MB||4000||650 MHz||1.15 GHz||65||$278|
|Third-Gen Core i5 Family|
|3570K||4/4||3.4 GHz||3.8 GHz||6 MB||4000||650 MHz||1.15 GHz||77||$212|
|3570T||4/4||2.3 GHz||3.3 GHz||6 MB||2500||650 MHz||1.15 GHz||45||$194|
|3570||4/4||3.4 GHz||3.8 GHz||6 MB||2500||650 MHz||1.15 GHz||77||$194|
|3550||4/4||3.3 GHz||3.7 GHz||6 MB||2500||650 MHz||1.15 GHz||77||$194|
|3550S||4/4||3.0 GHz||3.7 GHz||6 MB||2500||650 MHz||1.15 GHz||65||$194|
|3470||4/4||3.2 GHz||3.6 GHz||6 MB||2500||650 MHz||1.1 GHz||77||$174|
|3470T||2/4||2.9 GHz||3.5 GHz||3 MB||2500||650 MHz||1.05 GHz||35||$174|
|3470S||4/4||2.9 GHz||3.6 GHz||6 MB||2500||650 MHz||1.1 GHz||65||$174|
|3450||4/4||3.1 GHz||3.5 GHz||6 MB||2500||650 MHz||1.1 GHz||77||$174|
|3450S||4/4||2.8 GHz||3.5 GHz||6 MB||2500||650 MHz||1.1 GHz||65||$174|
We’re still looking at a dual-channel memory controller, though it’s now rated for DDR3-1600 data rates. Given the right memory, enthusiasts have the option to overclock as high as 2667 MT/s (up from 2133 MT/s) in more granular 200 MHz increments.
And although Ivy Bridge carries over Sandy Bridge’s 16 lanes of on-die PCI Express connectivity, we now have official PCIe 3.0 support for cards like AMD’s Radeon HD 7000s and Nvidia’s GeForce GTX 680.
All told, Ivy Bridge is yet another highly integrated processor design from Intel. Its pieces were constructed by independent teams throughout the world—engineers in Israel are responsible for the IA cores, a team in Folsom, CA built the graphics engine, and a second team in Folsom implemented the interconnects, cache, and system agent. Of course, a process development group up in Oregon made sure it’d all come together on the new 22 nm node.
What is the final product capable of? Let’s walk through Ivy Bridge step by step, exploring where it excels and digging into where it falls short of the community’s expectations.