AS SSD is very accurate with the C300
The reason your drive is slow is two fold, one being the chipset you are using, and second you need to use AHCI as mentioned.
Here is the changes you need to make in the registry, then reboot and set AHCI in the BIOS.
Enable switching between all IDE/AHCI/RAID modes by changing "Start" Values in these keys to 0 (Win 7 / Vista ONLY)
I would imagine the above would only apply if you use the default MSAHCI driver, if you can, unless it is possible to use the Intel chipset drivers on your board?
However, I am not 100% certain this applies to these boards due to the chipset used? What is the actual SB Chip on these boards, if its not ICHxx from intel then the above will only apply when using MSAHCI driver (Microsoft default driver)
You may want to try and find other users of this board and see what they are using for AHCI in regards to drivers and changing from IDE to AHCI.