September 7, 2009 9:00 PM PDT

Intel's new Core i7, Core i5 desktop chips bring faster CPUs to the mainstream

Update: Individual chip reviews are up around the Web, and the consensus seems to be universal admiration for the new Core i7's, and Core i5 especially, in terms of performance, value, and power efficiency. Scroll down to the bottom of this post for links to coverage from some of our favorite enthusiast sites.

Intel put itself far ahead of AMD technically last year with its Core i7 desktop CPUs, but the high-end prices for the Core i7 900 series made Intel's most advanced chip architecture more of a luxury than an industry standard. Monday's announcement of Intel's new, more affordable Core i7 800 series chips, as well as an even cheaper Core i5 CPU, will likely lead to Intel's most advanced chip penetrating the mainstream retail market.

Intel has three new chips to announce, as well as the new Intel P55 Express motherboard chipset to support them. The new Core i7's include the $562 2.93GHz Core i7 870, the $284 Core i7 860 at 2.8GHz, as well as the $196 2.6GHz Core i5 750 chip. Each is essentially a stripped-down version of its counterpart from the Core i7 900 series, the most affordable of which, the 2.66GHz Core i7 920, starts at about $280.

The technical sacrifices in the new chips are relatively minor. The new Core i7's have a double-channel memory interface, as opposed to triple-channel RAM in the Core i7 900's. That means new Core i7-based PC owners won't have quite as much RAM throughput, but they also save money by only having to buy two sticks of DDR3 at a time, as opposed to three with Core i7 900.

(Credit: Intel)

The sole Core i5 chip has the same two-channel memory limit, and Intel has also stripped out the Hyperthreading capability. Hyperthreading is an Intel technique that effectively doubles the number of processing threads (adding four virtual threads to the four physical CPU cores) depending on the workload. Heavy multitaskers and those who use multithreaded software will feel the loss here, although Intel's current mainstream Core 2 Quad family, which the Core i5 may replace, has no Hyperthreading either.

To build a desktop PC around either new chip, you'll also need a new motherboard using Intel's P55 Express chipset. We've already mentioned the change to the memory interface. The next most significant change has to do with the graphics bandwidth.

Like the old Core i7-compatible Intel X58-chipset motherboards, the P55 Express boards support multiple graphics cards via Nvidia's SLI and AMD's CrossFireX technologies. The difference with P55 is that you only get half the graphics data bandwidth as with X58. You still get full 16x PCI Express throughput if you use a single card on P55 Express, but install two cards and the graphics slots become two 8x slots, as opposed to full dual-16x on X58.

PC gamers on the cusp of purchasing a mainstream or a higher-end gaming PC may face a conundrum because of the graphics bandwidth limit. But for most price-sensitive gamers, one decent midrange 3D card will provide a more than adequate gaming experience, so the graphics bandwidth limit isn't a major loss for the new chipset's intended market.

So how fast are these new CPUs? We tested a PC from Falcon Northwest Talon with a Core i7 860 overclocked from 2.8GHz to 3.39GHz and found that it competed well against Core i7 920-based PCs that cost about $500 more. You can read the full review here. We also have a $1,300 Core i7 860-based system from Velocity Micro on deck for later this week.

For standalone chip reviews, PC Games Hardware found the Core i7 860 as fast or faster than either the Core i7 920, or AMD's Phenom II X4 965 on most of its benchmarks. The Core i5 even squeezed out a few wins of its own. The other enthusiasts sites haven't posted their coverage yet, and we'll add the appropriate links as other reviews come online, but the early results indicate that the new Core i7 and Core i5 will achieve Intel's goal of bringing its latest architecture available to mainstream consumers in a competitive package.

Enthusiast review links: