Key Specs
Intel LGA1366Four
3.2GHz
Intel QuickPath Interconnect
Intel’s new Core i7 processors don’t just live up to their hype—they exceed it. Representing a huge performance jump over previous generations, the Core i7 allows even midrange systems to leave the fastest Core 2 Extreme Edition CPUs in the dust. The initial chip lineup includes the $284 Core i7-920 running at 2.66GHz, the $562 Core i7-940 running at 2.92GHz, and the $999 Core i7-965 Extreme Edition running at 3.2GHz. The Core i7 Extreme Edition differs from the less-expensive chips because it features an unlocked multiplier, which simplifies overclocking, and a faster QuickPath communication bus.
All of the chips use Intel’s new LGA1366 socket, and at the moment only Intel’s X58 chipset supports the Core i7. The chip resembles a slightly larger version of the Core 2 Quad, but inside there are significant enhancements. All current Core i7 chips include four CPU cores on a single 45-nanometer die, but they appear to Windows as eight-core processors, as they bring back the Hyper-Threading feature found on the Pentium 4. Hyper-Threading lets a single CPU core tackle two code threads at one time, to minimize the amount of time that parts of a core sit idle. There are numerous other improvements in the silicon, including faster algorithms, new SSE4 text-processing instructions, better virtualization support, and a new 8MB shared L3 cache, in addition to each core’s 64K L1 cache and 256K L2 cache.
We compared the Core i7’s performance to Intel’s previous king of the hill, the $999 3.2GHz Core 2 Extreme QX9770, running on a 1,600MHz front-side bus (FSB). How much faster is the Core i7 than its Core 2 predecessors? Our Windows Media Encoder test, which uses only two CPU cores, saw the smallest performance increase but still managed to drop from 2 minutes and 55 seconds on the QX9770 to 2 minutes and 29 seconds on the i7-965, a 17 percent speedup. Our quad-core-aware Sony Vegas 8.0 video-editing tests showed the most dramatic improvement, dropping from 3 minutes and 43 seconds on the QX9770 to 2 minutes and 20 seconds on the i7-965 in our MPEG-2 tests and from 1 minute and 21 seconds to 50 seconds in our MPEG-4 render—59 and 62 percent speedups, respectively. Our iTunes conversion test took 3 minutes and 37 seconds on the QX9770, which dropped to 2 minutes and 46 seconds on the i7-965, a 30.7 percent improvement.
Even more impressive in the bang-for-the-buck department is the performance of the entry-level i7-920, which still managed to beat out the QX9770 in all of our productivity tests. Results ranged from a mere 1 percent speed increase in Windows Media Encoder to an 18 percent increase in the iTunes conversion test and an impressive 31 percent performance enhancement in our Vegas 8.0 MPEG-2 rendering test. On the other hand, most games don’t see much change, as modern games tend to rely more on graphics-card performance than CPU speed.
Some of the Core i7’s performance increase comes from its ability to access memory at a very high speed. The CPU has its own onboard memory controller, dispensing with the older FSB and replacing it with the new QuickPath Interconnect, which offers dramatically better bandwidth and takes the middleman (the FSB) out of the equation. To take full advantage of this bandwidth, you’ll need to team the Core i7 with triple-channel memory, that is, with three identical DDR3 DIMMs. (The Core i7/X58 chipset combo doesn’t support DDR2 memory.)
