|Intel DX79SI LGA2011 Desktop Motherboard|
|Reviews - Featured Reviews: Motherboards|
|Written by David Ramsey|
|Sunday, 13 November 2011|
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The Intel X79 Express Chipset
LGA2011 processors, like the Sandy Bridge Extreme series shown above, require the new X79 Express chipset. If you look at the block diagrams of the Z68 and X79 chipsets side by side, the X79 seems functionally identical to the Z68, except that it lacks the digital display support and Intel Smart Response Technology. The lack of the latter is disappointing, since our tests with Intel Smart Response Technology showed that its use of an SSD as an intelligent cache to a hard drive could dramatically improve storage performance. Perhaps to make up for this, the X79 does permit overclocking via raising the base clock (BCLK) frequency, something that's almost impossible on the previous Sandy Bridge chipsets since most of the other clocks on the board were derived from the base clock, and raising it more than a few MHz would make the entire board unstable.
Intel provides this handy block diagram of an LGA2011-based system with an X79 Express chipset:
As with the Z68 and earlier P67 chipsets, there are 14 USB 2.0 ports and 6 SATA ports, of which only two are SATA 6G. Notably missing is Intel's "Light Peak" (aka "Thunderbolt") interface, which Intel has touted as a reason for not supporting SuperSpeed USB 3.0. And it's really odd that only two of the SATA ports are SATA 6G, since 6G devices are becoming more common, especially among SSDs. For a cutting-edge platform, this is impossible to justify. At least AMD gives you a full six SATA 6G ports.
One nice thing is the abundance of PCI-E lanes, an area Intel has historically been a little skimpy on, especially on their LGA1155/1156 platforms. The Sandy Bridge E provides a full 40 PCI-E lanes from the processor, more than twice the 16 lanes of an LGA1155 Sandy Bridge CPU, and an additional eight lanes from the X79 chipset...the same as from the P67/Z68 chipsets. Together, that's a full 48 PCI-E lanes, besting even AMD's 42. Triple-card SLI/CrossFireX systems will run at 16/16/8 with eight lanes left over for SATA 6 and USB 3.0 use.
So the X79's a mixed bag: only two SATA 6G ports and no USB 3.0 or Thunderbolt, but plenty of PCI-E lanes.