Advanced Micro Devices Inc (AMD)

[Tim Fowler]

The latency to make one HT hop looks to be about 40 ns. Intel's northbridge latency is probably also in that vicinity. But now, here's the rub. HT needs to be converted into PCI Express. There's a translation latency as well as the standard PCI Express latency. In other words, Opteron has more latency when outputting a PCI Express signal than Intel's system.

I don't think Intel's Northbridge talks to the CPU in "PCI Express". Just as the signal on PCI-E needs to be converted to the type of signal used in HT the signal on PCI-E needs to be converted to whatever method or protocol Intel uses to communicate from the northbridge to the CPU.

Tim