Silly (probably) USB 3.0 adapter question!

I'm trying to eek a year or two out of my current computer, but knowing they're compatible with USB 2, I have bought a couple of External USB 3 drives.

If I were to get an adapter card to add USB 3 to my current rig, would an PCI-X slot be worthy?

It seems like most adapters use PCI-e slots, I only have one of those and my Video Card lives there.

I've tried to figure out the difference between a PCI-X and a PCI-Extended slot, but my mind chokes on 64 bit vs 32 bit vs multi-lane vs etc. etc.

Hope I've made sense here ... Tia!

~Lash

I'm not sure what you mean by PCI-X. Most boards have some combination of PCIe X16 slots, PCIe X8 slots, PCIe X4 slots, and PCIe X1 slots. Also found are some legacy (older) PCI slots. Any USB 3.0 adaptor card you find for any of those slots will work.

Here is a discription of the different slots if you want to brush up. But it's not necessary if you just want to plug it in and go.
PCI Express: http://en.wikipedia.org/wiki/PCI_Express
PCI: http://en.wikipedia.org/wiki/Conventional_PCI

You must be dealing with a server motherboard if you have a PCI-X slot. I'm not familiar with them. According to a quick research I did, they are a high speed version of PCI.
http://en.wikipedia.org/wiki/PCI-X

I'll leave the server boards to someone wiser than myself in that catagory. Do you have a free PCI slot? Or a PCI express slot?

This is a USB 3.0 expansion card for a PCI-X slot. Maybe this is what you are looking for.
http://www.amazon.com/Sabrent-PCIX [...] B003C1U9LE

Here's another supplier that it is available at:
http://www.tigerdirect.com/applica [...] &CatId=511