Supermicro AOC-SAT2-MV8

Hi,

I'm looking into getting another drive and have noticed I've run out of 
SATA ports (and EIDE, as it happens).

So, I'm looking at a PCI card for SATA and went back to look at that 
Supermicro AOC-SAT2-MV8 card - I've had my eye on it for a few years, or 
perhaps it was a previous version of the same thing, I'm not sure.

Anyway, I'm worried that it isn't the correct bus type for my computer. 
I'm confused by the PCI-X and PCIe types, and I don't have access to my 
computer over Christmas.

My motherboard is some consumer level MSI board, and I just added an 
nVidia graphics card on the same bus (it used one of the two longer slots).

Could someone with better knowledge of such things hazzard a guess?

Thanks,

Max.