PCI Bus, Southbridge, and PCI SATA Adapter Card

[Asrial]

Okay. So I have the ASUS K8V SE Deluxe motherboard. It has 2 Promise SATA ports and 2 VIA SATA ports. In my research I know that the VIA ports connect to the Southbridge and the I've 'read a lot' that the Promise connects into the PCI Bus.

People are saying to use the VIA ports because they're going to be faster as a result of this.

So my questions are... (and bear with me, I'm not a super tech with this area of motherboards)

Isn't the Southbridge going to be limited by the PCI Bus speeds as well? Isn't the PCI Bus just the underlying speed of everything on the motherboard?

The other part of this post...

I've been having a HELL of a time getting it to work. I can't get a fully functional SATA HD to detect at the BIOS level on the VIA controller and I can't get the Windows installation to detect it on the Promise controller (despite having the F6 drivers). It's a Hitachi so I have to use software to limit it to SATA I speed, but that software won't detect the HD on either controller.

So I'm looking at buying a PCI SATA adapter card. However, won't that card be the same as the Promise controller and be slower than the VIA controller? What's the difference between a $20 SATA adapter and a $100 SATA adapter? Do these adapters come with F6 drivers for a Windows installation?

 

[TemjinGold]

While I can't answer those questions, I CAN say if you are even entertaining the idea of a $100 Promise card, you would be MUCH better off just buying a new mobo instead.

 

[MerlinRML]

Originally posted by: Asrial

Isn't the Southbridge going to be limited by the PCI Bus speeds as well? Isn't the PCI Bus just the underlying speed of everything on the motherboard?

The PCI bus is a bus, but it's not the only bus. You need to look at a block diagram of your motherboard to figure out how all the chips are connected and by which bus at which speed.

For example, it's very common to have the southbridge connected with a dedicated PCIe 4x connection on current motherboards. Or in the AMD world, hypertransport connects to southbridge to the rest of of the motherboard. This gives you roughly 1GB/sec of bandwidth to share among all the devices that hang off the southbridge.

Look up your motherboard manual and you should be able to figure out what bandwidth you have.