With IntelNehalemMicroarchitectureRelease of processor, old FSB（Front end bus）WasQPI(Fast channel interconnection) bus (such as Bloomfield/Gulftown，Core i7-900 series), DMI bus (such asLynnfield/Clarkdale, Core i7-800 series, Core i5-700/600 seriesCore i3-500 series) to provide faster and more efficient data bandwidth for the new generation of processors, and the system bottleneck problem of FSB has also been solved.
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For example, on the P55 motherboard, we can no longer seeNorth BridgechipThere is only one chip called PCH (Platform Controller Hub) left to support peripherals.In the P55 platform, the North Bridge function has been completely integratedCPUAmong them, even the lastPCI-E busIt is also integrated into it.In this way, the CPUcontrol powerI gave it to myself, which is alsoLGA1156AndLGA1366The biggest difference, of course, is that its internal communication is still the QPI bus with an astonishing amount of data.The PCH chip is different from the originalNanqiao chipIt has more functions, but its nature is basically the same. It does not need to exchange too much data with the CPU, so DMI is enough for the connection bus.So, it seems that only 2.5GT/sIn essence, DMI bus has completely released the pressure of Beiqiao, and in return, it has higher performance.Although the Lynnfield (Core i7-800 series/Core i5-700 series) platform has physically changed from a three chip connection of "CPU North Bridge South Bridge" to a dual chip connection of "CPU-PCH", the QPI bus connection still exists, connecting the Lynnfield processor's "Core" and "UnCore (peripheral core, such as L1/L2/L3 Cache、MCH、PCI-E controllerAnd so on), while the UnCore part of the processor rather than the Core part communicates with the PCH chip through the DMI bus, which is actually the kind of "QPI or FSB bus from the CPU to the North Bridge chip, and DMI bus from the North Bridge chip to the South Bridge chip"Connection modeThe connection mode from three chips to chips has not changed in essence.Of course, we cannot compare the PCH chip with the previousICHThe South Bridge chip is the same, because in addition to inheriting the input and output functions of the traditional South Bridge chip, the PCH chip also undertakes the traditional North Bridge chips such as the Dispatch unit, the Management Engine unitNVRAMCell and Clock Buffers cell.However, although the function of PCH chip is more complex than that of traditional ICH South Bridge chip, there is not much communication between PCH chip and UnCore part of the processor, so an "ancient" DMI bus is enough to meet its needsData exchangeDemand.
