PCIE

Q

OK, I know it's an expansion slot. I also get that it comes in various widths (1x, 2x, 4x, 8x, 16x) and the cards are compatible one way but not the other (1x fits in everything else, but 8x doesn't fit in 4x or lower). What I don't get is the version #s and how they work. Also, is it really that hot?

-Q

Duff

Just a note, a PCI-Express slot can be physically x16, x8, whatever but only be connected at x4 or x1. This is more common on lower end boards.

Wikipedia wrote:

A PCIe card fits into a slot of its physical size or larger (maximum x16), but may not fit into a smaller PCIe slot (x16 in a x8 slot). Some slots use open-ended sockets to permit physically longer cards and negotiates the best available electrical connection. The number of lanes actually connected to a slot may also be less than the number supported by the physical slot size.

An example is a ×8 slot that actually only runs at ×1. These slots allow any ×1, ×2, ×4 or ×8 card, though only running at ×1 speed. This type of socket is called a ×8 (×1 mode) slot, meaning it physically accepts up to ×8 cards but only runs at ×1 speed. The advantage is that it can accommodate a larger range of PCIe cards without requiring motherboard hardware to support the full transfer rate. This keeps design and implementation costs down.

As for versions, I believe each revision increased bandwidth/data throughput or added other improvements/features.

The Wikipedia page on PCI Express is quite helpful and explains it much better than I can. http://en.wikipedia.org/wiki/PCI_Express

Not sure what you mean by is it hot. If you mean actual temperatures yes, modern graphics cards can get remarkably hot, my 5870s have peaked at 90C for short periods under full load. If you meant it's popularity, PCI Express has completely replaced AGP for graphics cards and it's quickly replacing PCI. I expect PCI slots to go the way of ISA within a couple years.

BlueSun

PCI-E is nice, but I wish the physical connectors were a little stronger. This isn't so much of a big deal with x16 cards, but definitely x1... it just feels too weak.

I kind of miss ISA in that respect, it thunked into place and you knew it wasn't going anywhere.

Same thing with SATA and PATA. I love SATA for its smaller cables and faster speeds, but the physical connector sucks.

Q

I tried the PCIE page on Wikipedia but it didn't say much to me as a prospective end user, which is why I was asking here.

-Q

BlueSun

Don't worry about the versions too much. Everything is pretty much backwards compatible. If you get a PCI-E 2.1 card, it should work fine in a PCI-E 3.0 slot and vice versa.

To get the most out of the card, try to match the versions or get a board that supports that version or higher.

For example, to get the most out of a 2.0 card, get a board with a 2.0 slot or higher.