Intel ICH9 reporting 1/4th size of an eSata disk array

First, Did you load the 'Intel Matrix' driver?, otherwise it is just a plain old sata controller.

Did you re-configure the disk array? The Cavalry come from the factory as 2 TB preconfigured (1.5TB as Raid 5) and supports Raid from the enclosure. You should not need (or try to use) the ICH9 Raid Controller on the motherboard.

I installed the Intel Matrix driver and it didn't work still...

I agree that the disk array was preconfigured for 1.5TB Raid 5. But then I can't explain why I am seeing only 500G. The GUI software that came on the DVD from cavalry keeps saying that there is no Silicon Image based raid controller on my machine. I haven't installed their card on my PC. My guess is that software works only if I install the eSata controller card they have shipped with the disk array. I haven't figured out how to configure the Cavalry array without the software they provided.

If they shipped a card with the array are they putting all the raid controls and a breakout port on the card and leaving just the disks in the array? If that is the case the only way to see more than 1 drive is to use their card or an equivilant raid controller card.

Sounds like your external drive cage is using a port multiplier. As far as I'm aware, the only manufacturer of port multipliers is Silicon Image, and the only controllers they work with are Silicon Image controllers. Therefore you will need to use their card.

One other note: When a port multiplier is connected to a controller that doesn't support port multipliers, it will look like a passthrough to port 0 of the port multiplier. I.e. since your ICH9 system doesn't support port multipliers, it will only see one of the disks in your external cage.

rockchalk yes you are right! I finally managed to talk to Cavalry customer support and they confirmed what you said. ICH9 doesn't have port multiplier and that I will have to install their card to see the array's full capacity.
I have another question... The card the array shipped with is a PCI card. Will the max Bandwidth of PCI be a bottleneck for getting the best performance out of this setup? The customer support rep told me that the alternate card that they offer is PCIe x1 and he said that it has less bandwidth than the PCI card.
From the wikipedia article (http://en.wikipedia.org/wiki/List_of_device_bandwidths) it looks like PCI 32-bit/33 MHz (1067 Mbps) < PCI Express x1 (2000 Mbps) < PCI 64-bit/33 MHz (or) PCI 32-bit/66 MHz (2133 Mbps)

* How do I find what is the spec of my PCI bus?
* Also can 4 HDDs (considering there can be concurrent reads from all 4 of HDDs) saturate the bandwidth provided by the above interfaces?

Yep, I missed that part somehow, you were trying to mix apples with oranges so to speak. Good catch and save rockchalk

ICH9 Hardware does support Port multiplier (Packet Mode), but the current drivers don't, should be suppertd Q2/Q3 2009.