Types of PCI Slots


OSNN Junior Addict
I am in the process of figuring out what I want in a new computer and am very confused at all the different kinds of PCI slots. I see motherboards with:

PCIe 2.0 x16 (at x16/x16/x1 or x16/x8/x8 mode)
PCIe 2.0 x16 (at x16 mode)
PCIe 2.0 x16 (at x8 mode)
PCIe 2.0 x16 (at x4 mode)
PCIe x4
PCIe x1
PCI 2.2

What are all these different configuration slots used for? There's probably more that I don't even know about.

Physically there seems to be 3-4 (maybe more?) configurations to these slots.

And what the heck is True @16 3-Way SLI?

What I am looking for is maximum expandability in a Motherboard.

I want to be able to add Controller cards for extra 1394 or extra IDE drives. Add a sound card. Or be able to add who knows what.

Any information you can give me about what all these PCI slots are about would be appreciated.

Dark Atheist

OSNN Veteran Addict
Staff member
Political User
pci-e is the type

x16 is the speed, much like it was on AGP cards

1_1 - 2.0 would be the specifcation of the pci-e standard - revision


.. Commodore ..
Political User
>> PCIe 2.0 x16 (at x16/x16/x1 or x16/x8/x8 mode) <<

That means PCI Express 2.0 which is what all cards are going to now. x16 is the speed for slot. For example: since that has x16/x16/x1, the speed would x16 in slots 1 & 2 and 1 in slot 3. If you run it in dual sli it will be x16 in both 1 & 2. If you run it in tri sli it will be x16 in slot 1 and x8 in slots 2 &3.

True @16 3-way sli is all three slots being at 16 speed ...


OSNN Veteran Addict
You can usually identify them on pictures as x16 capable slots will be longer than x8 and x4. If you'd like pictures let me know or you can dig through oodles and oodles of server pictures on my flickr account (see sig) :p


Staff member
Political User
At least some of the companies have pictures on the box of the three types of slots, AGP, PCI and PCIe and their relative size to each other and the things to look for when checking the motherboard to see what slot it has.

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