I have a motherboard from an old Dell GX-260. I'm intending to use it as a test bed for checking things out before I put them in the 'real' computer.

The board has three slots: an AGP slot and what appears to be 2 PCI slots. However, the second PCI slot has an additional 22 (I think) pins on a 'tail' and is longer than the other (conventional) PCI slot. So I'm thinking this is PCI-X or PCIe. A quick check showed it was not PCIe, and the documentation just refers to the board having 2 PCI slots. The picture in the manual does indeed show that one slot is longer than the other, but it makes no reference to it.

I'ce always seen PCI slots as being one size, but I may be mistaken.

So my question is: Is this just a standard PCI slot of a type I hadn't noticed before, or is it maybe a PCI-X slot, or what? As a side note, the board has gigabit ethernet, so there may be a high-speed bus floating around which could be used for PCI-X. I would think they's mention it, though, if that were the case.