PCI-X requirement?

I'm looking into buying a Decklink HD capture card for capturing and editing HD footage. One of the requirements is a "64 bit PCI-X slots 100MHz and 133MHz."
First I thought they meant PCI-Express. (It is express, right? or is it extreme?) But then I noticed- one of the graphics card requirements is PCI E x 16!
So what is PCI-X? Is this just the standard PCI slot? 64 bit though? I'm very confused.

Here is the full list of requirements for the Decklink HD:

Processor
• Intel Dual Xeon 2.8GHz or higher
Motherboard
• Intel 7505/7525 chipset – This includes motherboards such as Supermicro
X5DAE, X5DA8 and X6DA8 - G2
PCI slots
• 64 bit PCI-X slots 100MHz and 133MHz
Memory
• 2 GB ECC 2100 RAM
Graphics card
• AGP x 8 Graphics card (Not Matrox)
• PCI E x 16 (Nvidia FX1300)
Disk Arrays
• SCSI - Ultra 320 SCSI card (either PCI or onboard), with at least
8 x U320 SCSI disks, 10 000 rpm, software striped as RAID [0], OR;
• 2GB fibre Channel
• SCSI card recommendation - Adaptec 39320 series

And here's what I have:

Processor
• Athlon 64 3500 Socket 939 (so I could upgrade to an Athlon 64 X2 dual core)
Motherboard
• ASUS A8N-SLI Deluxe Socket 939 NVIDIA nForce4 SLI ATX
• 2 GB Non-ECC DDR400
Graphics card
• PCI E x 16 (Nvidia GeForce 6800 GT)
Disk Arrays
•2x 250Gb RAID 0 (500Gb total) Seagate 7200 RPM

So it would seem that my system is WAY off. I have no idea if it would work, I don't think I meet a single requirement.
If anyone can give me any insight, I would greatly appreciate it.
Thank you in advance!