Your images have been approved. I can now see that HD Tune’s read benchmark is indeed suggesting that your drive is running in PIO mode. That would account for the abyssmally slow 1MB/s transfer rate. If your drive were operating at its maximum potential, then the transfer rate would be around 100MB/s or better.
A good benchmark would look something like the following:
http://i52.tinypic.com/1zxr2j4.png
http://i57.photobucket.com/albums/g216/gtosu_ls/2T09.jpg
http://www.coolaler.com.tw/image/wd/Caviar_Green_2tb/11.jpg
Because the “problem” appears to be at the SATA data interface, it is difficult to lay the blame squarely on VIA’s controller. Therefore I can’t answer your question as to whether the drive would perform to its full potential with a different card.
As for returning the drive to DMA mode, apart from editing your Windows registry, you could simply switch to the second SATA port. This should force Windows to see the drive as a “new” device, and it should then revert to its DMA default. You may find that it eventually drops back to PIO mode, though.
To answer your 3Gbps question, I don’t believe you will derive any benefit from a 3Gbps interface speed. Since the drive’s maximum sustained transfer rate is only around 100MB/s, this means that you won’t even come close to the limits of a 1.5Gbps (~150MB/s) interface.
Lastly, I’m not a programmer, but AIUI your SMART software communicate with your HDD’s device driver either via general system calls, or via device specific IOCTLs. One method produces intelligible results, while the other does not. That’s not the fault of the HDD or the SATA controller.
