ATA66 headscratcher

I have an Abit BP6 with onboard Highpoint HPT366 - ATA66 controller. Does anybody know if the ATA66 bus speed runs proportionally to PCI bus by divisor. Or does it run at a constant 66Mhz bus with the PCI bus having no effect on the ATA66 bus. Or am I just spitting into the wind ???

The board does have its own bios that posts after the board posts.

as I understand it the Highpoint controller is actually on the PCI bus itself, just built in. IT should be affected by PCI bus speed like any other PCI card.

I'm pretty sure, but not 100%.

Yes, I believe that's correct, the controller is on the PCI bus.

It's hooked into the resources of PCI slot 3 and shares an IRQ with it. I never could see any significant difference though with HDtach and Sandra benchmarks when under- or overclocking my PCI bus. My guess is that the PCI speed only affects the rate of communication between the PCI-bus and the Highpoint controller chip itself, but has no real effect on the rate of communication between the Highpoint chip and the HDD's connected to it. Like it's a closed-loop, cuz many power management settings of the mobo also don't apply to it, they only apply to the integrated ATA controller of the mainboard's chipset.

Lancelot said:

My guess is that the PCI speed only affects the rate of communication between the PCI-bus and the Highpoint controller chip itself, but has no real effect on the rate of communication between the Highpoint chip and the HDD's connected to it. Like it's a closed-loop, cuz many power management settings of the mobo also don't apply to it, they only apply to the integrated ATA controller of the mainboard's chipset.

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Ok so when running at 66FSB (1/2) HPT should be running at (1/1) but what about 100 (1/3) or 124 (1/4)

is the HPT divisor proportional to the PCI divisor or is it overclocked at speeds over 66??

or possibly underclocked depending on FSB?