SATA II HD on a 32-bit PCI bus?

I have a Seagate ST3160812AS 160 GB SATA II (300 GB/s) hard drive jumpered for 150 GB/s operation on the 150 GB/s onboard SATA controller on my ASUS P4P800-E Deluxe motherboard. I would like to realize a little more of the speed potential of this drive, but I don’t have any PCI-X or PCI-Express slots available on this board for an add-on SATA II controller, only 32-bit PCI slots.

[SIZE=2]My question is - will any of the 32-bit PCI SATA II controllers, like the HighPoint RocketRAID 1720, 1740 or 1742, give me any speed increase with SATA II drives like the ST3160812AS or is the 32-bit PCI bus a limiting factor in getting anywhere near theoretical SATA II transfer speeds?

I know I’m probably not transferring data at 150 GB/s now and I’m sure nobody ever reaches the theoretical speeds these interfaces promise, but what I’d like to know is could I expect a significant increase in whatever transfer rates I’m getting now by using a 32-bit PCI SATA II controller, or am I just wasting my money?

You can run the same drive on an ATA133 controller and not see any difference in transfer speeds. In other words, the interface speed has no impact on the drive speed. At least not with the currently available drives. The PCI bus is loaded with tons of stuff running at all times, and so is dividing it’s available bandwidth with all of that. So the chipset-based SATA controller is by far the best bet for getting max sustained transfer speed. That drive will be lucky to break 50MB/sec [B]sustained[/B] transfers anyhow.

To the “OP”:

You will not be able to take anywhere near full advantage of SATA II bandwidth on any modern SATA hard drive, especially in single-drive systems. This is because the maximum sustainable (sequential) physical transfer rate of that particular Seagate 160GB hard drive (as well as most modern 7200 rpm hard drives) barely exceeds 72 MB/s, while the 300 MB/s maximum burst transfer rate is only between the drive’s cache and the SATA controller on the motherboard or card.

As for adding a SATA II controller card on the PCI bus, that is not recommended: You may actually experience slower real-world performance than if you used your motherboard’s native SATA I controller. The maximum total combined bandwidth of a motherboard’s entire 32-bit/33MHz PCI bus is only 133 MB/s, which is then shared between many different devices, reducing the available bandwidth to a PCI-based hard drive controller even further. What’s more, PCI-card-based hard drive controllers use SCSI-type drivers which add additional overhead and latency to the system, reducing overall performance still more. And since your motherboard and chipset predates the adoption of PCI-Express (PCI-E), the motherboard-embedded controller will give you the best performance.