Help me understand PCI Express terminology

[Denis54]

I am looking at 1156 motherboards and am confused about the terminology I read regarding PCI Express. All the boards I look at seem to have some different specifications.

Could you help me understand some of the specifications I have seen?

PCI Express 2.0 x16

PCI Express x16

1 x PCI Express 2.0 x16 slot (at x16 mode) 1 x PCI Express 2.0 x16 slot (at x4 mode, 2.5GT/s)

1 x PCIe 2.0 x16 (single at x16) 1 x PCI Express 2.0 x16 slots (@x4 mode, 2.5GT/s)

1 x PCI Express x16 slot, running at x16 (PCIEX16) 1 x PCI Express x16 slot, running at x8 (PCIEX8) Note: When dual graphics cards are used in 1st and 2nd PCIex16 slots, SATA3 / USB 3.0 (Marvell 9128 /NEC USB 3.0 Controllers) will work at normal mode.

2 x PCI Express x16 slots, running at x16 (PCIEX16_1/PCIEX16_2)

2 x PCI Express x16 slot, running at x8 (PCIEX8_1/PCIEX8_2)

 

[Quiksilver]

PCI Express 2.0 x16
A PCI Express Revision 2.0 slot that is physically 16 lanes.

PCI Express x16
Same as above but doesn't mention which PCI Express revision it is, but all modern boards use revision 2.

1 x PCI Express 2.0 x16 slot (at x16 mode) 1 x PCI Express 2.0 x16 slot (at x4 mode, 2.5GT/s)
1x PCI Express Revision 2.0 slot that is physically and electrically 16 lanes.
1x PCI Express Revision 2.0 slot that is physically 16 lanes but only 4 lanes electrically.

1 x PCIe 2.0 x16 (single at x16) 1 x PCI Express 2.0 x16 slots (@x4 mode, 2.5GT/s)
Same as above

1 x PCI Express x16 slot, running at x16 (PCIEX16) 1 x PCI Express x16 slot, running at x8 (PCIEX8) Note: When dual graphics cards are used in 1st and 2nd PCIex16 slots, SATA3 / USB 3.0 (Marvell 9128 /NEC USB 3.0 Controllers) will work at normal mode.
1x PCI Express Revision 2.0 slot that is physically and electrically 16 lanes.
1x PCI Express Revision 2.0 slot that is physically 16 lanes but only 8 lanes electrically.

2 x PCI Express x16 slots, running at x16 (PCIEX16_1/PCIEX16_2)
2x PCI Express Revision 2.0 slot that is physically and electrically 16 lanes.

2 x PCI Express x16 slot, running at x8 (PCIEX8_1/PCIEX8_2)
2x PCI Express Revision 2.0 slot that is physically and electrically 8 lanes.

See answers within the quote.

 

[teddyv]

I am glad someone posted this - I am planning a new build and this has been pretty much gibberish to me too. I understand the 16x slot is for graphics cards, and the other slots are for add-on cards like sound, RAID, SATA, etc. What is the difference between the small 1x slots and the larger regular PCI slots (besides the physical size of course...)

 

[Denis54]

So should I conclude that 2x PCI Express Revision 2.0 slot that is physically and electrically 16 lanes is the best solution?

If not, what should I look for?