Hardware: Core i7-3960X, Intel DX79SI, Radeon HD 6850
The test sample Intel provided to our German crew is the same as the one that landed in the U.S.: the six-core Sandy Bridge-E chip branded as Core i7-3960X. It is specified to run at a base frequency up to 3.3 GHz with all six cores, but Turbo Boost 2.0 can take it up to 3.9 GHz when one or two cores are active.
In order to ensure maximum thermal headroom, we also received a closed-loop liquid cooling kit designed by Asetek and very similar to the products offered by Antec, Corsair, Cooler Master, and Cool IT. Interestingly, the solution provided here is not as large or as powerful as the one AMD delivered with its FX sample. We'll use the same liquid cooler when we analyze efficiency at overclocked settings in the very near future. Intel plans to make it available somewhere between $85-100, and it should fit all current Intel platforms.
There aren't many folks who'd spring for a $1000 CPU and the handicap it with insufficient cooling. So, we're using the closed-loop system for our efficiency exploration at stock clocks today. The result of ample cooling is better heat dissipation, which results in Turbo Boost holding its elevated clock rates for longer stretches without running into thermal bottlenecks.
Intel’s DX79SI is the company's highest-end motherboard, competing against products from ASRock, Asus, ECS, Evga, Gigabyte, and MSI, amongst others. If history is any indication, Intel's own retail platforms tend to be more conservative than the flagships from its third-party board partners. As such, they're generally not the first choice of hardcore enthusiasts. Now, that doesn't mean Intel's team isn't capable of designing a great motherboard; in fact, the DX79SI is perhaps its best effort to date. Notably, eight DIMM slots and three PCI Express slots represent inclusions that any power user is going to demand.
Thus, the DK79SI represents a good, stable platform for us to test on. It's not loaded with the number of features you'd expect to find on some of the more extravagant boards that Thomas is in the process of rounding up. However, it facilitates all of Sandy Bridge-E's performance, it enables its salient features, and it's stable.
The DX79SI comes armed with lots of USB 2.0 connectivity, a couple of USB 3.0 ports, gigabit Ethernet, and six SATA ports (two of which operate at data rates as high as 6 Gb/s), as well as software-based RAID support. The X79 Platform Controller Hub facilitates eight lanes of second-gen PCIe connectivity, while the processor contributes 40 lanes of PCI Express 3.0, which drive the board's three 16-lane slots.
Intel’s highest-end thermal solution is manufactured by Asetek, but it’s not a true high-end part as far as liquid cooling is concerned.