After all the details about the new iMacs and news about SATA 3.0 and 450Mbps Wi-Fi, the Hardmac.com today highlighted another curiosity: its AMD Radeon graphics chipset connected to the CPU via a 16x PCI Express interface.
In the latest MacBooks Pro, the PCI Express 8x to enable your Thunderbolt port to be connected directly to the logic board and thus not have compromised performance.
In the case of the new iMacs, however, we already know that they use a BD82Z68 chip from Intel which allows Thunderbolt to be connected by the graphics chipset without any loss of performance (even in full use and even with two Thunderbolt ports, as in the case of 27-inch iMacs).
In the future, Intel's "Ivy Bridge" processors will have many more PCI Express links, which would rule out the need for any concerns related to this by Apple and other PC makers.
(tip from Leandro F. Pippa)