Intel Ivy Bridge-E review

Intel launched its Haswell processors a couple of months ago with a line-up that included the super-fast Core i7-4770K. But the chipmaker has continued to churn out high-performance processors and the 270 Haswell part is eclipsed by the 847 Ivy Bridge-E based Core i7-4960X.

Ivy Bridge-E chips are retooled versions of Xeon processors, and they use last year's silicon for two simple reasons: businesses want stable technology that doesn't have to be upgraded often, and these parts are the only Intel chips with six Hyper-Threaded cores.

There are three new chips. The flagship i7-4960X, which is the one on test runs at 3.6GHz, and one core can use Turbo Boost to hit 4GHz. It's got six cores that can address twelve concurrent tasks, and 15MB of L3 cache.

The i7-4930K still has six cores, but they're clocked to 3.4GHz with a peak of 3.9GHz and there's "just" 12MB of cache. The weakest of the three, the i7-4820, has four cores that run at 3.7GHz, with a top Turbo speed of 3.9GHz, and 10MB of cache.

All three of the new chips are unlocked for easy overclocking, but none include integrated graphics.

The Ivy Bridge-E architecture

The new chips don't have new silicon, but Intel made improvements to the Ivy Bridge-E processors in several areas. Its 22nm manufacturing process is a step ahead of Sandy Bridge's 28nm process, and it's allowed Intel to shrink the chip and use more efficient transistors. The i7-4960X fits 1.86 billion transistors inside a 257mm2 package, a reduction from the 2.27 billion transistors that filled out the i7-3960X's 435mm2 chip.

This is the first Intel mainstream chip to be officially specified with 40 PCI-Express 3.0 lanes, which paves the way for huge graphics power while Sandy Bridge also had 40 lanes, they were only compatible with PCI-Express 2.0. There's support for quad-channel DDR3 memory that runs at 1,866MHz an upgrade from the 1,600MHz modules that worked with Sandy Bridge-E.

There's better branch prediction, improved out-of-order execution, and double the amount of cache bandwidth than in Sandy Bridge-E all improvements that aid the flow of tasks through these complex, Hyper-Threaded quad- and six-core processors.

Sockets and chipsets

The architecture has been upgraded, but the LGA 2011 socket and X79 chipset remain unchanged from the hardware that debuted with Sandy Bridge-E.

That means existing coolers still work, as will most motherboards manufacturers have released BIOS updates that make older hardware compatible. There's only one company that isn't updating its boards to work with Ivy Bridge-E, and that's Intel a decision which strikes us as odd.

The reliance on the older chipset results in two annoying trade-offs. There's no native USB 3 support, and the chipset can only handle two SATA 6Gpb/s connections. Manufacturers solder third-party controllers to boards, but these extra chips increase prices and lead to potential stability issues.