True ... I was generalizing, even PCIe does not have BW exceeding the QPI ... nothing you do, regardless to the QPI BW will help, the flow of information will be limited elsewhere. Although, I don't recall the BW for the DMI interface between NB/SB, it is probably faster than USB or firewire.
Same thing with HyperTransport. The link to the NB/SB chipsets are not the rate limiters, hence performance will only be retarded if one supresses the HT BW below the BW of the tested link.
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